Method and apparatus for determining anticoagulant therapy factors

ABSTRACT

Methods and apparatus are disclosed for determining a new anticoagulant therapy factors for monitoring oral anticoagulant therapy to help prevent excessive bleeding or deleterious blood clots that might otherwise occur before, during or after surgery. New anticoagulant therapy factors maybe based upon the time to maximum acceleration from the time of reagent injection (TX) into a plasma sample, Embodiments include methods and apparatus for determining an anticoagulant therapy factor without requiring use of a mean normal prothrombin time determination or ISI, and may be carried out with the patient sample and a coagulation reagent.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 11/906,325, filed on Oct. 1, 2007, which is a continuation-in-part of U.S. application Ser. No. 11/359,667, filed on Feb. 22, 2006, which is a continuation-in-part of U.S. application Ser. No. 10/662,043, filed on Sep. 12, 2003, which is a continuation of U.S. application Ser. No. 10/428,708 filed on May 2, 2003, the complete disclosures of which are hererin incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to analyzing blood for carrying out coagulation studies and other chemistry procedures, including monitoring oral anticoagulant therapy to take into account the platelet count in determining prothrombin times (PT), and providing new Anticoagulant Therapy Factors that are useful in diagnosing and treating individuals in relation to blood conditions.

2. Description of the Prior Art

Testing of blood and other body fluids is commonly done in hospitals, labs, clinics and other medical facilities. For example, to prevent excessive bleeding or deleterious blood clots, a patient may receive oral anticoagulant therapy before, during and after surgery. Oral anticoagulant therapy generally involves the use of oral anticoagulants—a class of drugs which inhibit blood clotting. To assure that the oral anticoagulant therapy is properly administered, strict monitoring is accomplished and is more fully described in various medical technical literature, such as the articles entitled “PTs, PR, ISIs and INRs: A Primer on Prothrombin Time Reporting Parts I and II” respectively published November, 1993 and December, 1993 issues of Clinical Hemostasis Review, and herein incorporated by reference.

These technical articles disclose anticoagulant therapy monitoring that takes into account three parameters which are: International Normalized Ratio (INR), International Sensitivity Index (ISI) and prothrombin time (PT), reported in seconds. The prothrombin time (PT) indicates the level of prothrombin and blood factors V, VII, and X in a plasma sample and is a measure of the coagulation response of a patient. Also affecting this response may be plasma coagulation inhibitors, such as, for example, protein C and protein S. Some individuals have deficiencies of protein C and protein S. The INR and ISI parameters are needed so as to take into account various differences in instrumentation, methodologies and in thromboplastins' (Tps) sensitivities used in anticoagulant therapy. In general, thromboplastins (Tps) used in North America are derived from rabbit brain, those previously used in Great Britain from human brain, and those used in Europe from either rabbit brain or bovine brain. The INR and ISI parameters take into account all of these various factors, such as the differences in thromboplastins (Tps), to provide a standardized system for monitoring oral anticoagulant therapy to reduce serious problems related to prior, during and after surgery, such as excessive bleeding or the formation of blood clots.

The ISI itself according to the WHO 1999 guidelines, Publication no. 889-1999, have coefficients of variation ranging from 1.7% to 8.1%. Therefore, if the ISI is used exponentially to determine the INR of a patient, then the coefficients of variation for the INR's must be even greater than those for the ISI range.

As reported in Part I (Calibration of Thromboplastin Reagents and Principles of Prothrombin Time Report) of the above technical article of the Clinical Hemostasis Review, the determination of the INR and ISI parameters are quite involved, and as reported in Part II (Limitation of INR Reporting) of the above technical article of the Clinical Hemostasis Review, the error yielded by the INR and ISI parameters is quite high, such as about up to 10%. The complexity of the interrelationship between the International Normalized Ratio (INR), the International Sensitivity Index (ISI) and the patient's prothrombin time (PT) may be given by the below expression (A),

wherein the quantity

$\begin{matrix} \left\lbrack \frac{{{Patient}'}s\mspace{14mu} {PT}}{{Mean}\mspace{14mu} {of}\mspace{14mu} {PT}\mspace{14mu} {Normal}\mspace{14mu} {Range}} \right\rbrack & (A) \end{matrix}$

is commonly referred to as prothrombin ratio (PR):

$\begin{matrix} {{INR} = \left\lbrack \frac{{{Patients}'}s\mspace{14mu} {PT}}{{Mean}\mspace{14mu} {of}\mspace{14mu} {PT}\mspace{14mu} {Normal}\mspace{14mu} {Range}} \right\rbrack^{ISI}} & (B) \end{matrix}$

The possible error involved with the use of International Normalized Ratio (INR) is also discussed in the technical article entitled “Reliability and Clinical Impact of the Normalization of the Prothrombin Times in Oral Anticoagulant Control” of E. A. Loeliger et al., published in Thrombosis and Hemostasis 1985; 53: 148-154, and herein incorporated by reference. As can be seen in the above expression (B), ISI is an exponent of INR which leads to the possible error involved in the use of INR to be about 10% or possibly even more. A procedure related to the calibration of the ISI is described in a technical article entitled “Failure of the International Normalized Ratio to Generate Consistent Results within a Local Medical Community” of V. L. Ng et al., published in Am. J. Clin. Pathol. 1993; 99: 689-694, and herein incorporated by reference.

The unwanted INR deviations are further discussed in the technical article entitled “Minimum Lyophilized Plasma Requirement for ISI Calibration” of L. Poller et al. published in Am. J. Clin. Pathol. February 1998, Vol. 109, No. 2, 196-204, and herein incorporated by reference. As discussed in this article, the INR deviations became prominent when the number of abnormal samples being tested therein was reduced to fewer than 20 which leads to keeping the population of the samples to at least 20. The paper of L. Poller et al. also discusses the usage of 20 high lyophilized INR plasmas and 7 normal lyophilized plasmas to calibrate the INR. Further, in this article, a deviation of +/−10% from means was discussed as being an acceptable limit of INR deviation. Further still, this article discusses the evaluation techniques of taking into account the prothrombin ratio (PR) and the mean normal prothrombin time (MNPT), i.e., the geometric mean of normal plasma samples.

The discrepancies related to the use of the INR are further studied and described in the technical article of V. L. NG et al. entitled, “Highly Sensitive Thromboplastins Do Not Improve INR Precision,” published in Am. J. Clin. Pathol., 1998; 109, No. 3, 338-346 and herein incorporated by reference. In this article, the clinical significance of INR discordance is examined with the results being tabulated in Table 4 therein and which are analyzed to conclude that the level of discordance for paired values of individual specimens tested with different thromboplastins disadvantageously range from 17% to 29%.

U.S. Pat. No. 5,981,285 issued on Nov. 9, 1999 to Wallace E. Carroll et al., which discloses a “Method and Apparatus for Determining Anticoagulant Therapy Factors” provides an accurate method for taking into account varying prothrombin times (PT) caused by different sensitivities of various thromboplastin formed from rabbit brain, bovine brain or other sources used for anticoagulant therapy. This method does not suffer from the relatively high (10%) error sometimes occurring because of the use of the INR and ISI parameters with the exponents used in their determination.

The lack of existing methods to provide reliable results for physicians to utilize in treatment of patients has been discussed, including in a paper by Davis, Kent D., Danielson, Constance F. M., May, Lawrence S., and Han, Zi-Qin, “Use of Different Thromboplastin Reagents Causes Greater Variability in International Normalized Ratio Results Than Prolonged Room Temperature Storage of Specimens,” Archives of Pathol. and Lab. Medicine, November 1998. The authors observed that a change in the thromboplastin reagent can result in statistically and clinically significant differences in the INR.

Considering the current methods for determining anticoagulant therapy factors, there are numerous opportunities for error. For example, it has been reported that patient deaths have occurred at St. Agnes Hospital in Philadelphia, Pa. There the problem did not appear to be the thromboplastin reagent, but rather, was apparently due to a failure to enter the correct ISI in the instrument used to carry out the prothrombin times when the reagent was changed. This resulted in the incorrect INR's being reported. Doses of coumadin were given to already overanticoagulated patients based on the faulty INR error, and it is apparent that patient deaths were caused by excessive bleeding due to coumadin overdoses. In the St. Agnes Hospital, Philadelphia 2001 INR disaster, an incorrect ISI of 1.01 was used instead of 2.028. As has been recommended by Poller, INR studies should be performed at the INR 2.0 and 3.0 levels. 2.0 to 3.0 is the Therapeutic INR Range recommended for most clotting/thrombotic conditions. These two levels will be used in the following calculations:

The PRs at INR 2.0 calculation are:

INR=PR^(ISI); log INR=(ISI)(log PR);

log PR=log INR/ISI;

log PR=log 2.0=0.301; log PR/ISI=0.301/1.01=0.298

PR=1.986

INR=PR^(ISI)=1.986^(1.01)=2.00

INR=PR^(ISI)=1.986^(2.028)=4.02

An INR of 2.00 would have been reported, not the actual 4.02. Warfarin at a reported INR 2.0 level would likely have been administered to an already overanticoagulated patient, but serious consequences may not necessarily have occurred here. Using the erroneous 1.01 ISI with an INR of 3.0 for calculations is drastically different:

log PR=log INR/ISI=0.477/1.01=0.472

PR=2.968

INR=PR^(ISI)=2.968^(1.01)=3.00

INR^(ISI)=2.968^(2.028)=9.08

This incorrectly reported INR of 3.0 would actually have been 9.08. 9.08 is well above INR=6.0 where excessive bleeding is considered to occur. In addition, the five fatal St. Agnes cases, even at INR=9.08, could have even been administered a routine warfarin dose, since it would have been believed it was intended for patients with an INR of 3.0, not 9.08.

But even in addition to errors where a value is not input correctly, the known methods for determining anticoagulant therapy factors still may be prone to errors, even when the procedure is carried out in accordance with the reagent manufacturer's ISI data. One can see this in that current methods have reported that reagents used to calculate prothrombin times, may, for healthy (i.e., presumed normal) subjects, give rise to results ranging from 9.7 to 12.3 seconds at the 95th % reference interval for a particular reagent, and 10.6 to 12.4 for another. The wide ranges for normal patients illustrates the mean normal prothrombin time differences. When the manufacturer reference data ranges are considered, if indeed 20 presumed normal patients' data may be reported within a broad range, then there is the potential for introduction of this range into the current anticoagulation therapy factor determinations, since they rely on the data for 20 presumed normal patients. Considering the reagent manufacturer expected ranges for expected normal prothrombin times, INR units may vary up to 30%. This error is apparently what physicians must work with when treating patients. A way to remove the potential for this type of error is needed.

This invention relates to the inventions disclosed in U.S. Pat. Nos. 3,905,769 ('769) of Sep. 16, 1975; 5,197,017 ('017) dated Mar. 23, 1993; and 5,502,651 ('651) dated Mar. 26, 1996, all issued to Wallace E. Carroll and R. David Jackson, and all of which are incorporated herein by reference. The present invention provides apparatus and methods for monitoring anticoagulant therapy.

SUMMARY OF THE INVENTION

Methods and apparatus useful for processing coagulation studies, and other chemistry procedures involving blood and blood components. The apparatus and methods may be used to determine anticoagulant therapy factors which are designated herein, in particular, to determine new Anticoagulant Therapy Factors (nATF's) which preferably may replace International Normalized Ratio (INR) in anticoagulation therapy management. Previously, anticoagulation therapy involved the use of International Normalized Ratios (INR's). The International Normalized Ratio (INR) was utilized in order to arrive at an anticoagulant therapy factor (ATF). The INR based ATF was dependent on the prothrombin time (PT), the prothrombin ratio (PR), a fibrinogen transformation rate (FTR), and a maximum acceleration point (MAP) having an associated time to maximum acceleration (TMA).

Methods and apparatus are disclosed for determining a new anticoagulant therapy factor (nATF) for monitoring oral anticoagulant therapy to help prevent excessive bleeding or deleterious blood clots that might otherwise occur before, during or after surgery. In one embodiment, a new anticoagulant therapy factor (nATF) is based upon a determination of the fibrinogen transformation rate (FTR) which, in turn, is dependent on a maximum acceleration point (MAP) for fibrinogen (FBG) conversion. The nATF quantity is also based upon the time to maximum acceleration from the time of reagent injection (TX) into a plasma sample, but does not require the difficulty of obtaining prior art International Normalized Ratio (INR) and International Sensitivity Index (ISI) parameters. The International Normalized Ratio (INR) was created to relate all species' clotting material to human clotting material, and nATF can replace INR in anticoagulant therapy management.

In accordance with other embodiments, methods and apparatus are provided for determining an anticoagulation therapy factor, which do not require the use of a mean normal prothrombin time (MNPT) and ISI data. In other words, the need to obtain and calculate the prothrombin time of 20 presumed normal patients, is not required to determine an anticoagulant therapy factor.

In accordance with the present invention, there is provided apparatus and methods for carrying out coagulation studies and other chemical procedures and analyses.

Another embodiment provides methods and apparatus for determining an anticoagulant therapy factor or INR, such as INRn, from the derivation of clotting curve values in connection with a designated area defined by clotting curve data. One preferred embodiment relates to an area defined by clotting curve data that corresponds with the area of a trapezoid formed along the clotting curve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of potentiophotometric apparatus constructed in accordance with one embodiment of the present invention for determining blood chemistry analyses such as coagulation studies, including determination of the new anticoagulant therapy factor (nATF), where the output of the analog/digital (A/D) converter is applied to a computer.

FIG. 2 is a plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process.

FIG. 3 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process.

FIG. 4 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process.

FIG. 5 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process illustrating the fibrinogen lag phase.

FIG. 6 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process involves a trapezoidal configuration formed by points along the clotting curve.

FIG. 7 is an illustration showing a preferred embodiment of a trapezoidal representation formed based on data from the clotting curve reaction, as shown in FIG. 6.

FIGS. 8, 9, 10 and 11 are Bland-Altman plots representing data from Table 16.

DETAILED DESCRIPTION

Referring to the drawings, wherein the same reference numbers indicate the same elements throughout, there is shown in FIG. 1 a light source 4 which may be a low power gas laser, or other light producing device, producing a beam of light 6 which passes through a sample test tube, such as the container 8, and is received by detection means which is preferably a silicon or selenium generating photocell 10 (photovoltaic cell). Battery 12 acts as a constant voltage DC source. Its negative terminal is connected through switch 14 to one end of variable resistor 16 and its positive terminal is connected directly to the opposite end of variable resistor 16. The combination of battery 12 and variable resistor 16 provides a variable DC voltage source, the variable voltage being derivable between line 18 at the upper terminal of resistor 16 and wiper 20. This variable DC voltage source is connected in series with detection means photocell 10, the positive output of detection means photocell 10 being connected to the wiper 20 of variable resistor 16 so that the voltage produced by the variable voltage DC source opposes the voltage produced by the detection means photocell 10. The negative output of detection means photocell 10 is connected through variable resistor 22 to line 18. Thus, the voltage across variable resistor 22 is the difference between the voltage produced by the variable voltage DC source and the voltage produced by the photovoltaic cell 10. The output of the electrical network is taken between line 18 and wiper 24 of variable resistor 22. Thus, variable resistor 22 acts as a multiplier, multiplying the voltage produced as a result of the aforesaid subtraction by a selective variable depending on the setting of variable resistor 22. The potentiophotometer just described embodies the electrical-analog solution to Beer's Law and its output is expressed directly in the concentration of the substance being measured.

Wiper 24 is illustrated placed at a position to give a suitable output and is not varied during the running of the test. The output between line 18 and wiper 24 is delivered to an A/D converter 26 and digital recorder 28. As is known, the A/D converter 26 and the digital recorder 28 may be combined into one piece of equipment and may, for example, be a device sold commercially by National Instrument of Austin, Tex. as their type Lab-PC+. The signal across variable resistor 22 is an analog signal and hence the portion of the signal between leads 18 and wiper 24, which is applied to the A/D converter 26 and digital recorder 28, is also analog. A computer 30 is connected to the output of the A/D converter 26, is preferably IBM compatible, and is programmed in a manner described hereinafter.

For example, preferably, the detector cell 10 is positioned adjacent an opposite wall of the sample container 8, and the emitter light source 4 positioned adjacent on opposite wall, so the light 6 emitted from the light source 4 passes through the container 8. The light source 4 is preferably selected to produce light 6 which can be absorbed by one or more components which are to be measured.

The apparatus can be used to carry out coagulation studies in accordance with the invention. In accordance with a preferred embodiment of the present invention, the light source 4 may, for example, comprise a light emitting diode (LED) emitting a predetermined wavelength, such as for example, a wavelength of 660 nm, and the detector cell 10 may, for example, comprise a silicon photovoltaic cell detector. Optionally, though not shown, a bar code reader may also be provided to read bar code labels placed on the sample container 8. The bar code reader may produce a signal which can be read by the computer 30 to associate a set of data with a particular sample container 8.

To carry out a coagulation study on blood plasma, the citrated blood is separated from the red blood cell component of the blood. Conventional methods of separation, which include centrifugation, may be employed. Also, the use of a container device such as that disclosed in our issued U.S. Pat. No. 6,706,536, may also be used, and the method disclosed therein for reading the plasma volume relative to the sample volume may also be employed.

Illustrative of an apparatus and method according to one embodiment is a coagulation study which can be carried out therewith. A reagent, such as, for example, Thromboplastin-Calcium (Tp-Ca), is added to the plasma sample which is maintained at about 37° C. by any suitable temperature control device, such as a heated sleeve or compartment (not shown). The reagent addition is done by dispensing an appropriate amount of the reagent into the plasma portion of the blood. The plasma portion may be obtained by any suitable separation technique, such as for example, centrifugation. In one embodiment illustrated herein, the container 8 is vented when reagent is added. The reagent for example, may comprise thromboplastin, which is added in an amount equal to twice the volume of the plasma. The reagent is mixed with the plasma. It is preferable to minimize air bubbles so as not to interfere with the results. The plasma sample to which the reagent has been added is heated to maintain a 37° C. temperature, which, for example, may be done by placing the container holding the plasma and reagent in a heating chamber (not shown).

Readings are taken of the optical activity of the components in the sample container 8.

Reaction kinematics may be studied by observing changes in the optical density of the plasma layer. For example, an amount of reagent, such as Thromboplastin-Calcium (Tp-Ca), may be added to the plasma sample in the container. The plasma sample in the container may comprise a known amount of volume. Alternately, the plasma volume may be ascertained through the method and apparatus described in our U.S. Pat. No. 6,706,536. A controlled amount of Tp-Ca reagent is added to the plasma sample. The amount of reagent added corresponds to the amount of plasma volume. The detector cell 10 and emitter light source 4 are preferably positioned so the absorbance of the plasma sample may be read, including when the reagent is added and the sample volume is thereby increased.

With the detection elements, such as the cell 10 and emitter 4, positioned to read the plasma sample and the reagents added thereto, the reaction analysis of the extended prothrombin time curve can be followed. FIG. 2 shows a graph of a plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process. The change in optical density of the plasma level occurs after reagents have been added. The optical density of the plasma sample is monitored, as optically clear fibrinogen converts to turbid fibrin.

The coagulation study of the type described above is used to ascertain the results shown in the graph plotted on FIG. 2. The description of the analysis makes reference to terms, and symbols thereof, having a general description as used herein, all to be further described and all of which are given in Table 1.

TABLE 1 SYMBOL TERM GENERAL DESCRIPTION PT Prothrombin Time A period of time calculated from the addition of the reagent (e.g., thromboplastin-calcium) to a point where the conversion of fibrinogen to fibrin begins (i.e. the formation of the first clot). TMA Time to Maximum The time from PT to a point where the rate of conversion Acceleration of fibrinogen to fibrin has reached maximum and begins to slow. MAP Maximum Acceleration Point A point where the fibrinogen conversion achieves maximum acceleration and begins to decelerate. EOT End of Test Point where there is no appreciable change in the polymerization of fibrin. TEOT Theoretical End Of Test The time to convert all fibrinogen based on the time to convert the fibrinogen during the simulated Zero Order Kinetic rate. TX (or T₂) Time to Map Time to reach the Maximum Acceleration Point (MAP) from point of injection. MNTX Mean Normal Time to Map The mean of the times of at least 20 normal people to reach then Maximum Acceleration Point (MAP). FTR Fibrinogen Transformation The amount of fibrinogen converted during a particular Ratio time period. This is a percentage of the total Fibrinogen. ATF Anticoagulation Therapy The calculated value used to monitor the uses of an Factor anticoagulant without a need for an International Sensitivity Index (ISI) of a thromboplastin. nATF new Anticoagulation Therapy A replacement for the INR to provide a standardized Factor system for monitoring oral anticoagulant therapy. (Also expressed as ATFt and ATFz) PR Prothrombin Ratio A value computed by dividing a sample PT by the geometric mean of at least 20 normal people (MNPT). INR International Normalized A parameter which takes into account the various factors Ratio involved in anticoagulation therapy monitoring to provide a standardized system for monitoring oral anticoagulant therapy. ATFt Anticoagulation Therapy Utilizing a calculated Theoretical End Of Test value and Factor Theoretical the Natural Log “e” to removed the need for an MNPT. XR Time to MAP Ratio The value computed by dividing a sample “TX” by the geometric mean of at least 20 normal people “MNTX”.

Prior patents for obtaining an anticoagulant therapy factor (ATF) relied on the International Normalized Ratio (INR) system which was derived in order to improve the consistency of results from one laboratory to another. The INR system utilized the calculation of INR from the equation:

INR=(PT_(patient)/PT_(geometric mean))^(ISI)

wherein the PT_(patient) is the prothrombin time (PT) as an absolute value in seconds for a patient, PT_(geometric mean) is the mean, a presumed number of normal patients. The International Sensitivity Index (ISI) is an equalizing number which a reagent manufacturer of thromboplastin specifies. The ISI is a value which is obtained through calibration against a World Health Organization primary reference thromboplastin standard. Local ISI (LSI) values have also been used to provide a further refinement of the manufacturer-assigned ISI of the referenced thromboplastin in order to provide local calibration of the ISI value.

For illustration, the present invention can be employed for accurate determination of a new Anticoagulant Therapy Factor (nATF) from a human blood sample, for use during the monitoring of oral anticoagulant therapy, without the need for an ISI or LSI value, and without the need for an INR value as traditionally determined from the above equation (using a patient's prothrombin time and the prothrombin time from a geometric mean of individuals). As is known in the art, blood clotting Factors I, II, V, VII, VIII, IX and X are associated with platelets (Bounameaux, 1957); and, among these, Factors II, VII, IX and X are less firmly attached, since they are readily removed from the platelets by washing (Betterle, Fabris et al, 1977). The role of these platelet-involved clotting factors in blood coagulation is not, however, defined. The present invention provides a method and apparatus for a new Anticoagulant Therapy Factor (nATF) which may be used for anticoagulant therapy monitoring without the need for INR.

The International Normalized Ratio (INR) is previously discussed in already incorporated reference technical articles entitled “PTs, PRs, ISIs and INRs: A Primer on Prothrombin Time Reporting Part I and II respectively,” published in November, 1993 and December, 1993 issues of Clinical Hemostasis Review. The illustrative example of an analysis which is carried out employing the present invention relies upon the maximum acceleration point (MAP) at which fibrinogen conversion achieves a maximum and from there decelerates, the time to reach the MAP (TX), and the mean normal time to MAP (MNTX), and a fibrinogen transformation rate (FTR), that is, the thrombin activity in which fibrinogen (FBG) is converted to fibrin to cause clotting in blood plasma.

More particularly, during the clotting steps used to determine the clotting process of a plasma specimen of a patient under observation, a thromboplastin (Tp) activates factor VII which, activates factor X, which, in turn, under catalytic action of factor V, activates factor II (sometimes referred to as prothrombin) to cause factor IIa (sometimes referred to as thrombin) that converts fibrinogen (FBG) to fibrin with resultant turbidity activity which is measured, in a manner as to be described hereinafter, when the reaction is undergoing simulated zero-order kinetics.

From the above, it should be noted that the thromboplastin (Tp) does not take part in the reaction where factor Ia (thrombin) converts fibrinogen (FBG) to fibrin which is deterministic of the clotting of the plasma of the patient under consideration. The thromboplastin (Tp) only acts to activate factor VII to start the whole cascade rolling. Note also that differing thromboplastins (Tps) have differing rates of effect on factor VII, so the rates of enzyme factor reactions up to II-IIa (the PT) will vary.

Therefore, the prothrombin times (PTs) vary with the different thromboplastins (Tps) which may have been a factor that mislead authorities to the need of taking into account the International Normalized Ratio (INR) and the International Sensitivity Index (ISI) to compensate for the use of different types of thromboplastins (Tps) during the monitoring of oral anticoagulant therapy. It is further noted, that thromboplastins (Tps) have nothing directly to do with factor Ia converting fibrinogen (FBG) to fibrin, so it does not matter which thromboplastin is used when the fibrinogen transformation is a primary factor.

The thromboplastin (Tp) is needed therefore only to start the reactions that give factor Ia. Once the factor Ia is obtained, fibrinogen (FBG) to fibrin conversion goes on its own independent of the thromboplastin (Tp) used.

In one embodiment, the present method and apparatus has use, for example, in coagulation studies where fibrinogen (FBG) standard solutions and a control solution are employed, wherein the fibrinogen standard solutions act as dormant references to which solutions analyzed with the present invention are compared, whereas the control solution acts as a reagent that is used to control a reaction. The fibrinogen standards include both high and low solutions, whereas the control solution is particularly used to control clotting times and fibrinogens of blood samples. It is only necessary to use fibrinogen standards when PT-derived fibrinogens (FBG's) are determined. In connection with other embodiments of the invention, fibrinogen (FBG) standards are not necessary for the INR determination (such as for example INRz described herein).

Another embodiment provides a method and apparatus for determining an anticoagulation therapy factor which does not require the use of fibrinogen standard solutions. In this embodiment, the apparatus and method may be carried out without the need to ascertain the mean normal prothrombin time (MNPT) of 20 presumed normal patients.

Where a fibrinogen standard solution is utilized, a fibrinogen (FBG) solution of about 10 g/l may be prepared from a cryoprecipitate. The cryoprecipitate may be prepared by freezing plasma, letting the plasma thaw in a refrigerator and then, as known in the art, expressing off the plasma so as to leave behind the residue cryoprecipitate. The gathered cryoprecipitate should contain a substantial amount of both desired fibrinogen (FBG) and factor VIII (antihemophilic globulin), along with other elements that are not of particular concern to the present invention. The 10 g/l fibrinogen (FBG) solution, after further treatment, serves as the source for the high fibrinogen (FBG) standard. A 0.5 g/l fibrinogen (FBG) solution may then be prepared by a 1:20 (10 g/l/20=0.5 g/l) dilution of some of the gathered cryoprecipitate to which may be added an Owren's Veronal Buffer (pH 7.35) (known in the art) or normal saline solution and which, after further treatment, may serve as a source of the low fibrinogen (FBG) standard.

The fibrinogen standard can be created by adding fibrinogen to normal plasma in an empty container. Preferably, the fibrinogen standard is formed from a 1:1 fibrinogen to normal plasma solution. For example, 0.5 ml of fibrinogen and 0.5 ml of plasma can be added together in an empty container. Thromboplastin calcium is then added to the fibrinogen standard. Preferably, twice the amount by volume of thromboplastin is added into the container per volume amount of fibrinogen standard which is present in the container. The reaction is watched with the apparatus 10.

Then, 1 ml of each of the high (10 g/l) and low (0.5 g/l) sources of the fibrinogen standards may be added to 1 ml of normal human plasma (so the cryoprecipitate plasma solution can clot). Through analysis, high and low fibrinogen (FBG) standards are obtained. Preferably, a chemical method to determine fibrinogen (FBG) is used, such as, the Ware method to clot, collect and wash the fibrin clot and the Ratnoff method to dissolve the clot and measure the fibrinogen (FBG) by its tyrosine content. The Ware method is used to obtain the clot and generally involves collecting blood using citrate, oxalate or disodium ethylenediaminetetraacetate as anticoagulant, typically adding 1.0 ml to about 30 ml 0.85% or 0.90% sodium chloride (NaCl) in a flask containing 1 ml M/5 phosphate buffer and 0.5 ml 1% calcium chloride CaCl₂, and then adding 0.2 ml (100 units) of a thrombin solution. Preferably, the solution is mixed and allowed to stand at room temperature for fifteen minutes, the fibrin forming in less than one minute forming a solid gel if the fibrinogen concentration is normal. A glass rod may be introduced into the solution and the clot wound around the rod. See Richard J. Henry, M.D., et al., Clinical Chemistry: Principals and Techniques (2^(nd) Edition) 1974, Harper and Row, pp. 458-459, the disclosure of which is incorporated herein by reference. Once the clot is obtained, preferably the Ratnoff method may be utilized to dissolve the clot and measure the fibrinogen (FBG) by its tyrosine content. See “A New Method for the Determination of Fibrinogen in Small Samples of Plasma”, Oscar D. Ratnoff, M.D. et al., J. Lab. Clin. Med., 1951: V.37 pp. 316-320, the complete disclosure of which is incorporated herein by reference. The Ratnoff method relies on the optical density of the developed color being proportional to the concentration of fibrinogen or tyrosine and sets forth a calibration curve for determining the relationship between optical density and concentration of fibrinogen. The addition of a fibrinogen standard preferably is added to the plasma sample based on the volume of the plasma.

As is known, the addition of the reagent Thromboplastin C serves as a coagulant to cause clotting to occur within a sample of citrated blood under test which may be contained in a container 8. As clotting occurs, the A/D converter 26 of FIG. 1 will count and produce a digital value of voltage at a predetermined period, such as once every 0.05 or 0.01 seconds. As more fully described in the previously incorporated by reference U.S. Pat. No. 5,197,017 ('017), these voltage values are stored and then printed by the recorder as an array of numbers, the printing being from left to right and line by line, top to bottom. There are typically one hundred numbers in the five groups representing voltage values every second and hence, one line represents one-fifth of a second in time (20×0.01 seconds). Individual numbers in the same column are twenty sequential numbers apart. Hence, the time difference between two adjacent numbers in a column is one-fifth of a second. The significance of these recorded values may be more readily appreciated after a general review of the operating principles illustrated in FIG. 2 having a Y axis identified as Fibrinogen Concentration (Optical Density) and an X axis identified in time (seconds).

FIG. 2 illustrates the data point locations of a clotting curve related to a coagulation study which illustrates the activation and conversion of fibrinogen to fibrin. In general, FIG. 2 illustrates a “clot slope” method that may be used in a blood coagulation study carried out for determining a new anticoagulant therapy factor (nATFa). The ATFa represents an anticoagulation therapy factor represented by the expression ATFa=XR^((2-nFTR)) wherein a maximum acceleration point is obtained, and nFTR=IUX/IUT, where IUX is the change in optical density from a time prior to the MAP time (t_(<MAP) which is t_(MAP) minus some time from MAP) to the optical density at a time after the MAP time (t_(>MAP) which is t_(MAP) plus some time from MAP); and wherein IUT=the change in optical density at the time t₁ to the optical density measured at time t_(EOT), where time t_(EOT) is the end of the test (EOT). The first delta (IUX) represents the fibrinogen (FBG) for MAP (−a number of seconds) to MAP (+a number of seconds) (that is the fibrinogen (FBG) converted from t_(<MAP) to t_(>MAP) on FIG. 2). The (IUT) represents fibrinogen converted from c₁ to c_(EOT) (that is the fibrinogen converted from t₁ to t_(EOT), see FIG. 2). The XR for the ATFa expression is XR=TX/MNTX, which is the ratio of time to map (TX) by the mean normal time to map of 20 presumed “normal” patients.

The study which measures the concentration of the fibrinogen (FBG) in the plasma that contributes to the clotting of the plasma and uses an instrument, such as, for example, the potentiophotometer apparatus illustrated in FIG. 1, to provide an output voltage signal that is directly indicative of the fibrinogen (FBG) concentration in the plasma sample under test, is more fully discussed in the previously incorporated by reference U.S. Pat. No. 5,502,651. The quantities given along the Y-axis of FIG. 2 are values (+ and −) that may be displayed by the digital recorder 28. The “clot slope” method comprises detection of the rate or the slope of the curve associated with the formation of fibrin from fibrinogen. The “clot slope” method takes into account the time to maximum acceleration (TX) which is the point at which fibrinogen conversion achieves a maximum and from there decelerates.

As seen in FIG. 2, at time to, corresponding to a concentration c₀, the thromboplastin/calcium ion reagent is introduced into the blood plasma which causes a disturbance to the composition of the plasma sample which, in turn, causes the optical density of the plasma sample to increase momentarily. After the injection of the reagent (the time of which is known, as to be described, by the computer 30), the digital quantity of the recorder 28 of FIG. 1 rapidly increases and then levels off in a relatively smooth manner and then continues along until the quantity c₁ is reached at a time t₀. The time which elapses between the injection of thromboplastin at to and the instant time t₁ of the quantity c₁ is the prothrombin time (PT) and is indicated in FIG. 2 by the symbol PT. As shown in FIG. 2, the baseline that develops after the thromboplastin (TP) is introduced or injected into the sample generally is thought to represent the “lag phase” of all of the enzymes preceding prothrombin converting to fibrin. The enzymes types and amounts may vary from person to person, and thus, this would demonstrate the potential for prothrombin times to vary between individuals.

An anticoagulant therapy factor (nATF) is determined. The optical density of a quantity c₁ directly corresponds to a specified minimum amount of fibrinogen (FBG) that must be present for a measuring system, such as the circuit arrangement of FIG. 1, to detect in the plasma sample that a clot is being formed, i.e., through the transformation of fibrinogen to fibrin. The quantities shown in FIG. 2 are of optical densities, which may be measured in instrument units, that are directly correlatable to fibrinogen concentration values. The quantity c₁, may vary from one clot detection system to another, but for the potentiophotometer system of FIG. 1, this minimum is defined by units of mass having a value of about 0.05 grams/liter (g/l).

Considering the clotting curve of FIG. 2, detection of a first predetermined quantity c₁ is illustrated occurring at a corresponding time t₁, which is the start of the clotting process. In accordance with one or more embodiments, this process may be monitored with the apparatus of FIG. 1 for determining a new anticoagulant therapy factor (nATF). The time t₁ is the beginning point of the fibrinogen formation, that is, it is the point that corresponds to the beginning of the acceleration of the fibrinogen conversion that lasts for a predetermined time, The acceleration of the fibrinogen conversion proceeds from time (t₁) and continues until a time t_(MAP), having a corresponding quantity c_(MAP). The time t_(MAP), as well as the quantity CMAP, is of primary importance because it is the point of maximum acceleration of the fibrinogen (FBG) to fibrin conversion and is also the point where deceleration of fibrinogen (FBG) to fibrin conversion begins. Further, the elapsed time from t₀ to t_(MAP) is a time to maximum acceleration from reagent injection (TX), shown in FIG. 2. Preferably, the conversion of fibrinogen to fibrin is quantified every 0.1 seconds. The time to maximum acceleration from reagent injection (TX) is defined as the point on the clotting curve time line where this conversion has reached its maximum value for the last time, simulating a zero-order kinetic rate. To facilitate ascertainment of the location point of the last maximum value, the delta value of two points at a fixed interval may be measured until this value begins to decrease. This value is tracked for a period of time, such as for example five seconds, after the first decreasing value has been determined. This facilitates ascertainment of the last point of what may be referred to as a simulated zero-order kinetic rate. Referring to FIG. 3, a zero order kinetic rate is illustrated by the line (L).

As shown in FIG. 2, a quantity c_(MAP) and a corresponding time t_(MAP) define a maximum acceleration point (MAP). Fibrin formation, after a short lag phase before the MAP, occurs for a period of time, in a linear manner. Fibrinogen (FBG) is in excess during this lag phase, and fibrin formation appears linear up to the MAP.

The deceleration of fibrinogen (FBG) to fibrin conversion continues until a quantity c_(EOT) is reached at a time t_(EOT). The time t_(EOT) is the point where the deceleration of the fibrinogen (FBG) to fibrin conversion corresponds to a value which is less than the required amount of fibrinogen (FBG) that was present in order to start the fibrinogen (FBG) to fibrin conversion process. Thus, because the desired fibrinogen (FBG) to fibrin conversion is no longer in existence, the time t_(EOT) represents the ending point of the fibrinogen (FBG) to fibrin conversion in accordance with the coagulation study exemplified herein, which may be referred to as the end of the test (EOT). The fibrinogen (FBG) to fibrin conversion has a starting point of t₁ and an ending point of t_(EOT). The differential of these times, t₁ and t_(EOT), define a second delta (IUT).

The “clot slope” method that gathers typical data as shown in FIG. 2 has four critical parameters. The first is that the initial delta optical density of substance being analyzed should be greater than about 0.05 g/l in order for the circuit arrangement of FIG. 1 to operate effectively. Second, the acceleration fibrinogen (FBG) to fibrin conversion should be increasing for a minimum period of about 1.5 seconds so as to overcome any false reactions created by bubbles. Third, the total delta optical density (defined by the difference in quantities c₁ and c_(EOT)) should be at least three (3) times the instrument value in order to perform a valid test, i.e., (3)*(0.05 g/l)=0.15 g/l. Fourth, the fibrinogen (FBG) to fibrin conversion is defined, in part, by the point (t_(EOT)) where the deceleration of conversion becomes less than the instrument value of about 0.05 g/l that is used to detect the clot point (t₁). As with most clot detection systems, a specific amount of fibrinogen needs to be present in order to detect a clot forming. Adhering to the four given critical parameters is an example of how the present apparatus and method may be used to carry out a coagulation study to determine a specific quantity of fibrinogen. In order for that specific amount of fibrinogen to be determined, it is first necessary to detect a clot point (t₁). After that clot point (t₁) is detected, it logically follows that when the fibrinogen conversion becomes less than the specific amount (about 0.05 g/l for the circuit arrangement of FIG. 1), the end point (t_(EOT)) of the fibrinogen conversion has been reached.

One embodiment of the method and apparatus is illustrated in accordance with the clotting curve shown in FIG. 3. The clotting curve of FIG. 3 illustrates the values ascertained in arriving at a new anticoagulation therapy factor (nATFz). The embodiment illustrates the determination of a new anticoagulation therapy factor (nATFz), expressed by the following formula:

nATFz=XR^((2-nFTR))  (1)

This embodiment utilizes a zero order line (L) to obtain a first delta, in particular IUXz, which is a first differential taken along the simulated zero order kinetic line (L), and preferably along the segment between the start of the simulated zero order kinetic (T₂S) to the last highest absorbance value (T₂) (i.e., preferably, the last highest absorbance value of a simulated zero order kinetic). As previously discussed, the acceleration of the fibrinogen conversion proceeds from a first time, here time (T₁) and continues, eventually reaching a time where the last highest delta absorbance value or maximum acceleration point (T₂) having a corresponding quantity c_(T2) is reached. The values for “T” correspond with times, and the values for “c” correspond with quantity, which may be measured in instrument units based on optical density readings (also referred to as optical density or o.d.). The time T₂, as well as the quantity c_(T2), is the point of maximum acceleration of the fibrinogen (FBG) to fibrin conversion and is also the point where deceleration of fibrinogen (FBG) to fibrin conversion begins. In this embodiment, IUXz is the change in optical density preferably from the beginning of the at the time T₂S at which the simulated zero order kinetic begins to the optical density at time T₂ which is the maximum acceleration point or the last highest delta absorbance value of a simulated zero order kinetic. FIG. 3 shows the differential IUXz taken between a preferred segment of the zero order line. The second delta in particular (IUTz) is the change in optical density at the time T₂S to the optical density measured at time T₃, where time T₃ is the end of the test (EOT).

The (IUXz) represents the fibrinogen (FBG) converted between time T₂S and T₂. The (IUTz) represents fibrinogen converted from the time T₂S to the end of the test or T₃.

The maximum acceleration ratio (XR) for this embodiment is calculated to arrive at the new alternate anticoagulation therapy factor (nATFz). The maximum acceleration ratio (XR) is defined as the time to maximum acceleration from reagent injection (TX) divided by the mean normal TX value of a number of presumed normal specimens (MNTX). For example, the mean normal TX value may be derived based on the value of 20 or more presumed normal specimens. The maximum acceleration ratio (XR) may be expressed through the following formula:

XR=TX/MNTX  (2)

The clotting curve of FIG. 3 illustrates the values ascertained in arriving at the new alternate anticoagulation therapy factor (nATFz). The new alternate anticoagulation therapy factor (nATFz) is preferably expressed by the following formula:

nATFz=XR^((2-nFTR))  (3)

with FTR being IUXz/IUTz.

The preferred IBM-compatible computer 30 of FIG. 1 stores and manipulates these digital values corresponding to related data of FIG. 3 and is preferably programmed as follows:

-   -   (a) a sample of blood where the plasma is available, such as,         for example, a sample of citrated blood, is obtained and placed         in an appropriate container, the computer 30, as well as the         recorder 28, sequentially records voltage values for a few         seconds before injection of theromboplastin. As previously         discussed, thromboplastin (tissue factor) is one of the factors         in the human body that causes blood to clot. Prothrombin is         another. Fibrinogen is yet another. Before injection of the         thromboplastin, the output from the A/D converter 26 is         relatively constant. When thromboplastin is injected into the         plasma sample in the container, a significant and abrupt change         occurs in the recorded voltage values of both the computer 30         and the recorder 28. This abrupt change is recognized by both         the recorder 28 and, more importantly, by the computer 30 which         uses such recognition to establish T_(o). The computer 30 may be         programmed so as to correlate the digital quantities of the A/D         converter 26 to the analog output of the detector means         photocell 10 which, in turn, is directly correlatable to the         fibrinogen (FBG) concentration g/l of the sample of blood         discussed with reference to FIG. 3;     -   (b) the computer 30 may be programmed to look for a digital         quantity representative of a critical quantity c₁, and when such         occurs, record its instant time T₁. (The time span between T_(o)         and T₁ is the prothrombin time (PT), and has an normal duration         of about 12 seconds, but may be greater than 30 seconds);     -   (c) following the detection of the quantity c₁, the computer 30         may be programmed to detect for the acceleration of fibrinogen         (FBG) to fibrin conversion. The computer 30 is programmed to         detect the maximum acceleration quantity c_(MAP) or c_(T2) as         illustrated in FIG. 3, and its corresponding time of occurrence         t_(MAP), which is T₂ in FIG. 3.     -   (d) the computer detects a quantity c_(EOT) occurring at time         t_(EOT). Typically, it is important that the rate of fibrin         formation increase for at least 1.5 seconds following the         occurrence of (T₁);     -   (e) The computer 30 is programmed to ascertain the value for the         time to start (T₂S) which corresponds with the time at which the         simulated zero order kinetic rate begins.     -   (f) following the detection of the acceleration of fibrinogen         conversion to detect the start time T₂S, the computer 30 is         programmed to detect for a deceleration of the fibrinogen         conversion, wherein the fibrinogen concentration decreases from         a predetermined quantity c_(MAP) to a predetermined quantity         c_(EOT) having a value which is about equal but less than the         first quantity c₁. The computer is programmed to ascertain a         first delta (IUTz), by determining the difference between the         quantity c_(T2S) and the quantity c_(EOT); and a second delta         (IUXz) by determining the difference between the quantity         c_(T2S) and the quantity c₂ (or c_(MAP)).     -   (g) the computer 30 manipulates the collected data of (a); (b);         (c); (d); (e) and (f) above, to determine the new fibrinogen         transfer rate (nFTR). The nFTR may be arrived at based on the         principle that if a required amount (e.g., 0.05 g/l) of         fibrinogen concentration c₁ is first necessary to detect a clot         point (T₁); then when the fibrinogen concentration (c_(EOT))         becomes less than the required amount c₁, which occurs at time         (T_(EOT)), the fibrinogen end point has been reached. More         particularly, the required fibrinogen concentration c₁ is the         starting point of fibrinogen conversion of the clotting process         and the less than required fibrinogen concentration c_(EOT) is         the end point of the fibrinogen conversion of the clotting         process.     -   (h) The computer now has the information needed to determine the         new fibrinogen transfer rate (nFTRz) which is expressed by the         following formula:

nFTRz=IUXz/IUTz  (4)

-   -   (i) data collected is manipulated by the computer 30 to         calculate the maximum acceleration ratio (XR), which is         expressed as TX divided by the mean normal TX value of at least         20 presumed normal specimens (MNTX):

XR=TX/MNTX  (2)

The MNTX value may be ascertained and stored in the computer for reference.

-   -   (j) the computer 30 now has the information needed to determine         the nATFz, (also referred to as INRz) which typically is         expressed as:

nATFz or INRz=XR^((2-nFTR))  (3)

where, in the exponent, the value 2 is the logarithm of the total fibrinogen, which, as expressed in terms of the optical density, is 100% transmittance, the log of 100 being 2.

The new anticoagulation therapy factor (nATFz) does not require an ISI value, as was previously used to determine anticoagulation therapy factors. The new anticoagulation therapy factor (nATFz) uses for its ascertainment the values extracted from the clotting curve (see FIG. 3), in particular (nFTRz) (determined based on IUXz and IUTz), and (TX). In carrying out coagulation studies, the new anticoagulant therapy factor (nATFz) may replace INR in anticoagulant therapy management.

The apparatus and method for obtaining a new anticoagulant therapy factor, (nATFz), may be accomplished without encountering the complications involved with obtaining the prior art quantities International Normalized Ratio (INR) and International Sensitivity Index (ISI).

The new anticoagulant therapy factor (nATFz or ATF) preferably is a replacement for the International Normalized Ratio (INR), hence it may be referred to as INRz. Existing medical literature, instrumentation, and methodologies are closely linked to the International Normalized Ratio (INR). The nATFz was compared for correlation with the INR by comparative testing, to INR quantities, even with the understanding that the INR determination may have an error of about ten (10) % which needs to be taken into account to explain certain inconsistencies.

Table 2, below, includes anticoagulant therapy factors obtained from patients at two different hospitals. The ATFz values were obtained, with GATFz representing one geographic location where patients were located and MATFz being another location. The ATFz was obtained as the new anticoagulant therapy factor, and as illustrated in Tables 4 and 5, below, compares favorably to results obtained for INR determinations.

Another alternate embodiment for determining a new anticoagulant therapy factor (ATFt) is provided. The alternate embodiment for determining ATFt eliminates the need for determining a mean normal prothrombin time (MNPT) (or MNXT) and ISI, saving considerable time and costs, and removing potential sources of error, as the MNPT (the expected value of MNPT's depending on the varying 20 presumed normals population) and ISI (generally provided by the manufacturer of the reagent—such as, for example, the thromboplastin, etc.) are not required for the determination of the ATFt. An alternate embodiment for determining ATFt is illustrated in accordance with the clotting curve shown in FIG. 4. The clotting curve of FIG. 4 illustrates values ascertained in arriving at the alternate new anticoagulation therapy factor (nATFt). The alternate new anticoagulation therapy factor (nATFt) is preferably expressed by the following formula:

nATFt=Value 1*Value 2  (4)

The alternate embodiment utilizes the zero order line (L) to obtain a first delta, in particular IUXz, which is a first differential taken along the simulated zero order kinetic line (L), and preferably along the segment between the start of the simulated zero order kinetic (T₂S) to the last highest absorbance value (T₂) (i.e., preferably, the last highest absorbance value of a simulated zero order kinetic). As previously discussed, the acceleration of the fibrinogen conversion proceeds from a first time, here time (T₁) and continues, eventually reaching a time where the last highest delta absorbance value or maximum acceleration point (T₂) having a corresponding quantity c_(T2) is reached. The time T₂, as well as the quantity c_(T2), is the point of maximum acceleration of the fibrinogen (FBG) to fibrin conversion and also is the point where deceleration of fibrinogen (FBG) to fibrin conversion begins. As illustrated on the clotting chart in FIG. 4, IUXz represents a change in optical density (o.d.) preferably from the beginning of the at the time T₂S at which the simulated zero order kinetic begins to the optical density at time T₂ which is the maximum acceleration point or the last highest delta absorbance value of a simulated zero order kinetic. The value IUXz is generally expressed in instrument units (corresponding to absorbance or percent transmittance) and may generally be referred to as optical density or o.d. FIG. 4 shows the differential IUXz taken between a preferred segment of the zero order line. The second delta in particular (IUTz) represents a change in optical density at a time T₂S to the optical density measured at a time T₃, where time T₃ is the end of the test (EOT).

The (IUXz) represents the fibrinogen (FBG) converted between time T₂S and T₂. The (IUTz) represents fibrinogen converted from the time T₂S to the end of the test or T₃.

The first value V1 corresponds to the value determined for the theoretical end of test (TEOT), which, as illustrated in the clotting curve representation in FIG. 4, is where the zero order kinetic line (L) crosses the line y=T₃. The value TEOT is the elapsed time to convert the total instrument units (TIU) at the zero order kinetic rate, which is representative of the fibrinogen in the sample undergoing the conversion to fibrin. In other words, the expression for the first value (V1), or TEOT, is:

V1=TEOT=ZTM/IUXz*IUTz  (5)

where ZTM is the time between Tmap (i.e., T₂ shown on FIG. 4) and T2S. ZTM may be generally represented by the following expression:

ZTM=T ₂ −T ₂ S  (6)

A second value, V2, also referred to as a multiplier, is determined based on the value T₂S. In the expression for the ATFt, the second value, V2, may be obtained by taking the value of the time (T₂S) corresponding to a second time (t2) or the maximum acceleration point (Tmap), and scaling this value. It is illustrated in this embodiment that the multiplier is derived from the natural log base “e”, which is 2.71828, scaled to provide an appropriately decimaled value. The scaling number used in the example set forth for this embodiment is 100. The second value (V2) may be expressed by the following relationship:

V2=T ₂ S/100e  (7)

where T₂S is the maximum acceleration point for the sample, and 100e is the value 100 multiplied by the natural log base “e” (2.71828) or 271.828. The new anticoagulation therapy factor according to the alternate embodiment may be expressed as follows:

nATFt=[(T ₂ −T ₂ S)/IUXz*IUTz]*[T ₂ S/M]  (8)

where M represents a multiplier. In the present example, the multiplier M, corresponds to the value 271.828 (which is 100 times the natural log base “e”).

An alternate embodiment of an anticoagulant therapy factor, ATFt2, which does not require the ascertainment of a mean normal prothrombin time (MNPT) or use of an ISI value, is derived using the expression (5), wherein the IUTz is replaced by the expression (IUTz+IULz). In this alternate expression the method is carried out to ascertain the values for Value1 and Value2, in the manner described herein, with Value 1 being obtained through expression (5.1):

V1=TEOT=ZTM/IUXz*(IUTz+IULz)  (5.1)

where IULz is time to convert the lag phase fibrinogen (FBG) measured along the ordinate between T1 and T2S. In expression 5.1, the theoretical end of test (TEOT) is set to include the time to convert the fibrinogen (FBG) in the lag phase of the clotting curve. FIG. 5 illustrates the fibrinogen lag phase and the TEOT obtained from the line L2, and shows the IULz. ATFt2 is expressed by the following:

nATFt2=[(T ₂ −T ₂ S)/IUXz*(IUTz+IULz)]*[T ₂ S/M]  (8.1)

The apparatus may comprise a computer which is programmed to record, store and process data. The zero order rate may be determined by ascertaining data from analyzing the sample, and optical density properties. One example of how this may be accomplished is using two arrays, a data array and a sub array. A data array may be ascertained by collecting data over a time interval. In one embodiment, for example, the data array may comprise a sequential list of optical densities, taken of a sample by an optical analytical instrument, such as, for example, a spectrophotometer, for a frequency of time. In the example, the frequency of sample data is taken every 100^(th) of a second. In this embodiment, a computer is programmed to record the optical density of the sample, every 100^(th) of a second. Two values, NOW and THEN, for the data array are provided for ascertaining the Prothrombin Time (PT) (which is the time point T₁), maximum acceleration point (MAP), and end of test point (EOT). Two time definitions may be specified, one being the interval between NOW and THEN on the clotting curve, which may be 2.72 seconds (272/100^(th) of a second), the second being the size of the filter used for signal averaging. NOW is the sum of the last 20 optical densities and THEN is the sum of the 10 prior data points 2.72 seconds prior to NOW. A graphical illustration is provided in FIG. 5. As illustrated in FIG. 5, four values are defined: SUM(NOW), SUM(THEN), AVERAGE(NOW) and AVERAGE(THEN). The average is the sum divided by the filter value.

The sub array may be defined as a sequential list of delta absorbance units. This may begin at T₁, the prothrombin time (PT), and continue until the last highest delta absorbance (delta A) has been detected, then continues an additional five (5) seconds to insure the last delta A has been found. A determination of T₂S may be accomplished by locating within the sub array, the first occurrence of when the sub array delta value is greater than or equal to 80% of the highest delta absorbance units. The first derivative is ascertained by computing the difference between (NOW) and (THEN). The PT is ascertained by determining the point prior to the positive difference between AVERAGE(THEN) and AVERAGE(NOW) for a period of 2.72 seconds or 272 ticks. The MAP is the point where the last highest difference between SUM(THEN) and SUM(NOW) has occurred. The computer may be programmed to store this delta A value in the sub array. The EOT may be ascertained by determining the point prior to where the difference between SUM(THEN) and SUM(NOW) is less than one.

Table 2 illustrates examples of samples, identified by ID numbers, along with corresponding data which compares the ATF values obtained for an ATF determined through the prior method, using ISI and INR values (represented as ATFa), an ATF determined through the use of a zero order kinetic reaction using the MNTX (nATFz), and an ATF determined without using the MNXT or ISI (nATFt). The data in table 2 represents universal laboratory data from combined locations for the patients listed. The data is based on analysis of absorbance data, storage of the data by the computer, such as, for example, with a storage device, like a hard drive, and retrieving the data and processing the data. The data, in the example represented in Table 2 was processed using the definitions and NOW and THEN intervals.

TABLE 2 ID AINR GINR GatfA GatfZ GatfT MINR MatfA MatfZ MatfT U0047 2.10 1.70 1.76 1.74 1.62 2.00 2.08 1.78 1.68 U0048 1.80 1.80 1.84 1.83 1.72 1.90 1.96 1.85 1.82 U0050 1.80 1.70 1.77 1.80 1.68 1.90 2.00 1.80 1.70 U0056 1.60 1.50 1.54 1.54 1.40 1.80 1.83 1.61 1.48 U0058 3.20 2.80 2.93 2.92 2.93 3.30 3.38 3.10 3.29 U0060 2.20 2.10 2.15 2.17 2.11 2.20 2.21 2.26 2.27 U0062 2.80 2.60 2.69 2.72 2.69 3.00 3.19 2.86 2.91 U0415 0.90 0.90 0.88 0.94 0.74 0.90 0.95 0.97 0.83 U0432 1.80 1.50 1.53 1.42 1.24 1.40 1.39 1.46 1.33 U0436 2.40 2.40 2.57 2.24 1.99 2.40 2.41 2.28 2.17 U0438 3.90 3.70 4.25 3.26 3.21 3.80 4.22 3.40 3.55 U0439 2.30 2.20 2.27 1.94 1.75 2.30 2.32 2.07 2.02 U0440 5.80 4.80 5.41 4.33 4.50 4.60 4.84 4.55 5.18 U0441 4.50 4.90 5.58 5.01 4.86 4.40 4.71 4.64 5.35 U0442 1.80 1.70 1.79 1.65 1.48 1.80 1.84 1.64 1.52 U0800 2.00 2.00 2.02 1.78 1.64 2.10 2.11 2.12 2.09 U0843 1.40 1.40 1.43 1.42 1.22 1.40 1.47 1.44 1.31 U0848 1.30 1.40 1.41 1.31 1.13 1.30 1.37 1.34 1.23 U0849 2.40 2.30 2.44 1.94 1.77 2.30 2.38 1.98 1.93 U0855 1.30 1.30 1.29 1.35 1.17 1.20 1.24 1.36 1.22 U0860 1.00 1.00 0.99 1.00 0.77 1.00 0.97 1.00 0.85 U0861 2.80 2.90 2.98 2.70 2.58 3.00 2.99 2.88 3.00 U0863 1.70 1.70 1.70 1.76 1.65 1.70 1.77 1.83 1.79 U0867 3.20 2.90 3.19 2.64 2.38 3.00 3.10 2.85 2.83 U0875 2.20 2.00 2.16 1.80 1.60 2.00 2.02 1.81 1.71 U1198 2.20 2.10 2.17 2.07 1.91 2.00 1.98 2.22 2.22 U1199 2.80 3.30 3.57 2.79 2.76 3.20 3.21 2.99 3.28 U1201 1.90 1.90 1.95 1.76 1.62 1.80 1.84 1.82 1.80 U1202 1.30 1.30 1.35 1.31 1.16 1.40 1.39 1.35 1.20 U1205 1.60 1.80 1.90 1.71 1.53 1.90 1.90 1.80 1.67 U1207 1.90 1.90 1.96 1.68 1.49 1.90 1.87 1.78 1.61 U1218 3.00 2.60 2.86 2.57 2.56 2.80 3.07 2.90 3.08 U1225 2.20 2.30 2.34 2.01 1.83 2.60 2.40 2.21 2.16 U1230 1.30 1.40 1.45 1.47 1.32 1.40 1.45 1.50 1.45 U1575 1.40 1.30 1.30 1.53 1.41 1.40 1.44 1.49 1.35 U1576 2.20 2.10 2.11 2.10 2.02 2.30 2.32 2.19 2.17 U1579 1.50 1.70 1.72 1.64 1.49 1.80 1.81 1.61 1.44 U1581 1.70 1.70 1.74 1.85 1.81 1.70 1.77 1.74 1.73 U1599 2.00 1.70 1.78 2.01 1.96 2.00 2.14 2.04 1.93 U1600 3.50 3.30 3.39 3.58 3.63 3.90 4.21 3.37 3.64 U1649 0.90 0.80 0.80 0.94 0.76 0.90 0.89 0.89 0.74 U3050 2.70 2.80 3.08 2.34 2.17 2.30 2.34 2.05 2.02 U3077 1.30 1.40 1.44 1.34 1.17 1.30 1.28 1.31 1.16 U3083 1.60 1.60 1.58 1.47 1.31 1.60 1.68 1.48 1.37 U3395 2.70 3.20 3.51 2.80 2.70 2.80 2.90 2.38 2.32 U3398 1.50 1.70 1.77 1.60 1.47 1.60 1.65 1.61 1.47 U3408 1.10 1.20 1.18 1.13 0.92 1.10 1.03 1.09 0.94 U3453 1.10 1.20 1.24 1.19 0.97 1.20 1.18 1.11 1.00 U3456 1.10 1.00 0.96 0.99 0.81 1.00 0.98 1.04 0.90 U3457 2.20 2.30 2.38 2.03 1.94 2.10 2.28 1.94 1.86 U3459 2.90 2.60 2.81 2.40 2.22 2.40 2.53 2.11 2.04 U3724 2.70 2.40 2.47 2.16 1.95 2.60 2.72 2.31 2.25 U4471 1.50 1.60 1.67 1.63 1.43 1.70 1.71 1.71 1.62 U4737 2.90 2.60 2.79 2.42 2.26 2.70 2.87 2.51 2.42 U4752 1.40 1.50 1.55 1.47 1.26 1.50 1.48 1.46 1.33 U4757 2.00 2.10 2.09 1.95 1.77 2.00 2.02 2.00 1.92 U4767 2.60 2.40 2.52 2.16 1.95 2.60 2.56 2.33 2.27 U4772 2.50 2.70 2.78 2.59 2.58 2.80 2.84 2.55 2.56 U4801 1.30 1.40 1.41 1.33 1.13 1.50 1.49 1.41 1.22 U5133 0.90 0.90 0.91 0.92 0.74 1.00 0.97 0.97 0.78 U5158 5.50 5.10 5.90 5.34 5.64 6.00 6.57 6.50 7.00 U5169 2.60 2.90 3.16 3.14 3.09 3.20 3.35 3.35 3.67 U5173 1.10 1.20 1.17 1.19 1.02 1.20 1.21 1.16 1.03 U5175 1.70 1.80 1.86 1.85 1.67 1.90 1.92 1.82 1.70 U5178 2.30 2.20 2.28 2.02 1.79 2.60 2.85 2.03 2.01 U5183 2.90 2.60 2.83 2.43 2.23 3.60 3.86 2.88 3.01 U5190 2.80 2.70 2.82 2.85 2.70 3.20 3.36 3.00 3.15 U5193 3.10 3.00 3.13 2.93 2.81 3.60 3.73 3.33 3.30 U5565 2.70 3.20 3.34 3.16 3.04 3.50 3.48 3.31 3.50 U5589 1.60 1.80 1.86 1.69 1.52 1.90 1.96 1.64 1.44 U5591 2.00 2.20 2.33 2.16 1.98 2.30 2.28 2.19 2.24 U5592 1.10 1.20 1.23 1.26 1.09 1.40 1.35 1.49 1.37 U5593 1.70 1.80 1.89 1.76 1.55 1.80 1.85 1.76 1.70 U5594 2.30 2.60 2.79 2.84 2.81 2.80 2.84 2.85 2.96 U5597 3.30 3.30 3.64 3.25 2.96 4.10 4.03 3.85 4.08 U5992 1.40 1.40 1.42 1.45 1.29 1.30 1.37 1.37 1.30 U5993 1.00 0.90 0.94 1.03 0.84 1.00 0.98 1.03 0.84 U6017 1.00 0.90 0.95 0.99 0.77 0.90 0.89 0.97 0.79 U6047 2.30 2.30 2.36 2.17 1.97 2.20 2.28 2.23 2.22 U6056 1.00 1.00 1.01 1.03 0.87 1.00 1.01 1.02 0.85 U6060 1.90 2.10 2.17 2.10 1.94 2.30 2.00 2.16 2.12 U6065 3.10 2.80 2.93 2.77 2.60 3.00 3.13 2.74 2.76 U6928 1.20 1.20 1.17 1.34 1.17 1.20 1.24 1.22 1.05 U6929 1.20 1.20 1.20 1.23 1.06 1.20 1.19 1.15 0.98 U6936 2.40 2.50 2.45 3.02 3.15 2.60 2.61 2.51 2.60 U6938 2.10 2.10 2.12 2.30 2.22 2.30 2.26 2.25 2.21 U6951 1.50 1.50 1.51 1.59 1.42 1.60 1.66 1.49 1.36 U6972 2.40 2.40 2.47 2.57 2.49 2.80 2.84 2.54 2.51 U6977 1.30 1.30 1.34 1.35 1.19 1.30 1.37 1.23 1.08 U6987 5.10 4.50 4.43 5.29 5.42 5.70 5.44 6.16 6.82 U7316 1.20 1.10 1.15 1.28 1.14 1.30 1.28 1.26 1.11 U7317 2.00 1.60 1.68 1.66 1.56 1.90 1.90 1.68 1.56 U7318 2.80 2.70 2.86 2.71 2.57 3.30 3.40 2.70 2.72 U7320 2.00 1.90 1.92 2.17 2.13 2.00 2.06 2.12 2.13 U7321 1.50 1.40 1.38 1.59 1.50 1.60 1.60 1.61 1.51 U7322 1.80 1.70 1.72 1.63 1.46 1.70 1.76 1.55 1.42 U7324 1.30 1.20 1.25 1.33 1.17 1.40 1.40 1.30 1.13 U7440 2.60 3.00 2.98 2.90 2.89 3.00 3.01 3.05 3.37 U7443 2.00 2.00 2.03 1.87 1.73 2.10 2.17 1.90 1.79 U7458 1.40 1.40 1.43 1.38 1.20 1.40 1.40 1.40 1.26 U7465 9.70 7.40 8.12 6.47 7.80 7.10 7.54 7.06 7.63 U7469 1.10 1.10 1.11 1.11 0.86 1.20 1.14 1.10 0.90 U7470 3.20 3.40 3.65 3.27 3.12 3.60 3.67 3.62 3.70 U7707 2.20 2.20 2.27 2.34 2.28 2.30 2.29 2.23 2.22 U7708 1.60 1.60 1.60 1.73 1.61 1.70 1.73 1.71 1.62 U7710 2.30 2.50 2.64 2.71 2.73 2.70 2.85 2.75 2.96 U7713 1.40 1.60 1.59 1.57 1.50 1.60 1.64 1.58 1.48 U7724 2.40 2.40 2.47 2.62 2.65 2.70 2.73 2.75 2.84 U7727 1.70 1.70 1.73 1.78 1.68 1.90 1.90 1.91 1.86 U7738 2.40 2.30 2.45 2.27 2.21 2.40 2.54 2.29 2.32 U7794 1.90 1.80 1.91 1.72 1.58 1.70 1.78 1.71 1.55 U8080 3.10 3.60 3.63 3.41 3.54 3.30 3.33 3.18 3.34 U8087 1.90 1.90 1.95 1.80 1.62 1.90 1.91 1.79 1.74 U8092 1.70 1.70 1.76 1.67 1.49 1.90 1.93 1.67 1.57 U8210 2.60 2.90 3.04 2.72 2.63 2.70 2.77 2.54 2.56 U8221 3.20 3.70 3.99 3.42 3.35 3.50 3.47 3.24 3.46 U8555 2.60 2.40 2.54 2.56 2.52 2.90 3.09 2.57 2.56 U8558 2.30 2.20 2.26 2.16 2.15 2.30 2.33 2.31 2.35 U8559 1.60 1.40 1.45 1.42 1.24 1.60 1.65 1.45 1.28 U8563 2.20 2.30 2.30 2.32 2.30 2.40 2.43 2.34 2.42 U8570 1.20 1.20 1.20 1.34 1.23 1.20 1.21 1.35 1.25 U8575 0.90 0.80 0.84 0.96 0.80 0.90 0.89 0.95 0.78 U9031 2.10 2.40 2.33 2.42 2.42 2.60 2.38 2.34 2.35 U9032 1.70 1.70 1.75 1.78 1.58 1.90 1.93 1.68 1.53 U9034 3.00 2.90 2.82 3.79 3.97 3.40 3.37 3.49 3.80 U9039 2.70 3.00 3.17 2.99 3.03 3.20 3.20 3.12 3.27 U9040 1.40 1.40 1.44 1.36 1.20 1.40 1.39 1.33 1.15 U9049 3.50 3.30 3.46 3.33 3.45 3.60 3.77 3.33 3.72 U9055 2.40 2.10 2.14 2.15 2.04 2.40 2.39 2.15 2.13

A statistical comparison of the above data from Table 2 is presented below in Tables 4 and 5. The value AINR in Table 2 represents the INR value obtained pursuant to the World Health Organization (WHO), using expressions (A) and (B) above. GINR and MINR correspond to INR values used to determine the comparison data set forth in Tables 4 and 5.

The determination of the new anticoagulant therapy factor (ATFt) may be carried out with a computer. According to one example, the gathering, storing, and manipulation of the data generally illustrated in FIG. 4, may be accomplished by computer 30 of FIG. 1 that receives digital voltage values converted, by the A/D converter 26, from analog voltage quantities of the photocell 10 detection means.

In accordance with one embodiment, the IBM-compatible computer 30 of FIG. 1 stores and manipulates these digital values corresponding to related data of FIG. 4 and may be programmed as follows:

-   -   (a) a sample of blood where the plasma is available, such as,         for example, a sample of citrated blood, is obtained and placed         in an appropriate container, the computer 30, as well as the         recorder 28, sequentially records voltage values for a few         seconds before injection of thromboplastin. As previously         discussed, thromboplastin (tissue factor) is one of the factors         in the human body that causes blood to clot. Prothrombin is         another. Fibrinogen is yet another. Before injection of the         thromboplastin, the output from the A/D converter 26 is         relatively constant. When thromboplastin is injected into the         plasma sample in the container, a significant and abrupt change         occurs in the recorded voltage values of both the computer 30         and the recorder 28. This abrupt change is recognized by both         the recorder 28 and, more importantly, by the computer 30 which         uses such recognition to establish T_(o). The computer 30 may be         programmed so as to correlate the digital quantities of the A/D         converter 26 to the analog output of the detector means         photocell 10 which, in turn, is directly correlatable to the         fibrinogen (FBG) concentration g/l of the sample of blood         discussed with reference to FIG. 3;     -   (b) the computer 30 may be programmed to look for a digital         quantity representative of a critical quantity c₁, and when such         occurs, record its instant time T₁. (The time span between T_(o)         and T₁ is the prothrombin time (PT), and has an normal duration         of about 12 seconds, but may be greater than 30 seconds);     -   (c) following the detection of the quantity c₁, the computer 30         may be programmed to detect for the acceleration of fibrinogen         (FBG) to fibrin conversion. The computer 30 is programmed to         detect the maximum acceleration quantity c_(MAP) or c_(T2) as         illustrated in FIG. 3, and its corresponding time of occurrence         t_(MAP), which is T₂ in FIG. 3.     -   (d) the computer detects a quantity c_(EOT) occurring at time         t_(EOT). Typically, it is important that the rate of fibrin         formation increase for at least 1.5 seconds following the         occurrence of (T₁); the computer determines a theoretical end of         test (TEOT) based on the determination of the zero order kinetic         rate. The computer may be programmed to determine the zero order         rate, which is expressed as a Line (L) in FIG. 4. The TEOT may         be determined by the corresponding time value (TEOT) along the         line L which corresponds with the quantity c_(EOT) (i.e., that         quantity corresponding to the time, T₃).     -   (e) following the detection of the maximum acceleration quantity         c_(T2) (also representing c_(MAP)) and the time T₂ (also         representing t_(MAP)) both of which define the maximum         acceleration point (MAP), and the TEOT, the computer is         programmed to determine a new fibrinogen transformation rate         (nFTR) covering a predetermined range starting prior to the         maximum acceleration point (MAP) and ending after the maximum         acceleration point (MAP). The elapsed time from T₀ to T₂ (which         is t_(MAP)) is the time to maximum acceleration (TMA), shown in         FIG. 4, and is represented by TX (i.e., time to MAP);     -   The new fibrinogen transformation rate (nFTR) has an upwardly         rising (increasing quantities) slope prior to the maximum         acceleration point (MAP) and, conversely, has a downwardly         falling (decreasing quantities) slope after the maximum         acceleration point (MAP).     -   The computer 30 is programmed to ascertain the value for the         time to start (T₂S) which corresponds with the time at which the         simulated zero order kinetic rate begins.     -   (f) following the detection of the acceleration of fibrinogen         conversion to detect the start time T₂S, the computer 30 is         programmed to detect for a deceleration of the fibrinogen         conversion, wherein the fibrinogen concentration decreases from         a predetermined quantity c_(MAP) to a predetermined quantity         c_(EOT) having a value which is about equal but less than the         first quantity c₁. The computer is programmed to ascertain a         first delta (IUTz), by determining the difference between the         quantity c_(T2S) and the quantity c_(EOT); and a second delta         (IUXz) by determining the difference between the quantity         c_(T2S) and the quantity c_(2(or CMAP).); the computer also         determines the value ZTM by determining the difference between         the time T₂ (which is Tmap) and the time T₂S;     -   (g) the computer 30 manipulates the collected data of (a); (b);         (c); (d), (e) and (f) above, to determine the new fibrinogen         transfer rate (nFTR). The nFTR may be arrived at based on the         principle that if a required amount (e.g., 0.05 g/l) of         fibrinogen concentration c₁ is first necessary to detect a clot         point (t₁); then when the fibrinogen concentration (c_(EOT))         becomes less than the required amount c₁, which occurs at time         (t_(EOT)), the fibrinogen end point has been reached. More         particularly, the required fibrinogen concentration c₁ is the         starting point of fibrinogen conversion of the clotting process         and the less than required fibrinogen concentration c_(EOT) is         the end point of the fibrinogen conversion of the clotting         process.     -   (h) the duration of the fibrinogen conversion of the clotting         process of the present invention is defined by the zero order         time period between T_(EOT) and T₂S and is generally indicated         in FIG. 3 as IUTz. The difference between the corresponding         concentrations c_(T2S) and cT2 is used to define a delta IUXz.         The computer now has the information needed to determine the         TEOT, which is expressed by the following formula:

TEOT=ZTM/IUXz*IUTz  (5)

-   -   The value TEOT may be assigned VALUE 1;     -   (i) data collected is manipulated by the computer 30 to         calculate a second value, VALUE 2, using T₂S and a multiplier M         (which in this example, in expression 7 below, is a fraction).         The computer may be programmed to use as a multiplier a value         based on the natural log base “e” (which is 2.71828), scaled by         a scaling value. Here, the scaling value is 100, and the         multiplier may be expressed as follows:

M=100e  (9)

-   -   VALUE 2 is determined using the information which the computer         has ascertained and stored, by the following expression:

VALUE 2=T2S/100e  (7)

The data may be ascertained and stored in the computer for reference.

-   -   (j) the computer 30 now has the information needed to determine         the nATFt, which typically is expressed as:

nATFt=VALUE 1*VALUE 2  (4)

The computer 30 may be used to manipulate and derive the quantities of expression (4) to determine a new anticoagulant therapy factor nATFt utilizing known programming routines and techniques. The data collected by a computer 30 may be used to manipulate and derive the new anticoagulant therapy factor (nATFt) of expression (4). Similarly, one skilled in the art, using known mathematical techniques may derive the theoretical end of test TEOT of expression (5) and the second value VALUE 2 of expression (7) which, in turn, are used to determine the new anticoagulant therapy (nATFt) of expression (4). In the nATFt determination, the determination is based on the patient's own sample, and does not rely on the determination of normal prothrombin times for the reagent used (e.g., thromboplastin, innovin or the like). With the nATFt, no longer does the accuracy of the quantities determined depend, in whole or part, on the number of specimens used, that is, the number of stable (or presumed stable) patients.

The new anticoagulation therapy factor (nATFt) does not require an ISI value, as was previously used to determine anticoagulation therapy factors. The new anticoagulation therapy factor (nATFt) uses for its ascertainment the values extracted from the clotting curve (see FIG. 4), in particular T₂S, Tmap, TEOT, c_(T2S), cmap and ceot. In determining the new anticoagulant therapy factor (nATFt), the ISI is not required, nor is the MNPT, or the need to obtain and calculate the prothrombin times (PT's) for 20 presumed normal patients. In carrying out coagulation studies, the new anticoagulant therapy factor (nATFt) may replace INR in anticoagulant therapy management. In addition, using the sample from the patient, the computer 30 has knowledge of the values obtained for the fibrinogen reaction, to ascertain the (nATFt).

It should now be appreciated that the present invention provides an apparatus and method for obtaining a new anticoagulant therapy factor (nATF) without encountering the complications involved with obtaining the prior art quantities International Normalized Ratio (INR) and International Sensitivity Index (ISI).

The new anticoagulant therapy factor (nATFt) preferably is a replacement for the International Normalized Ratio (INR). Existing medical literature, instrumentation, and methodologies are closely linked to the International Normalized Ratio (INR). The nATFt was compared for correlation with the INR by comparative testing, to INR quantities, even with the understanding that the INR determination may have an error of about +/−15%, at a 95% confidence interval, which needs to be taken into account to explain certain inconsistencies.

The hereinbefore description of the new anticoagulant therapy factor (nATFt) does correlate at least as well as, and preferably better than, studies carried out using the International Normalized Ratio (INR). For some comparisons, see the tables below, and in particular Table 4 and Table 5.

Table 3 (Part A) and Table 3 (Part B) provide corresponding data for a coagulation study. In Table 3 (Part A and B), the following references are used:

Column Label Definition A ID Sample ID B OD@T₂S OD at the start of Zero Order Kinetic C OD@Map OD at the Maximum Acceleration Point (MAP) D OD@Eot OD at the END OF TEST (Eot) E ΔT₂SMap Delta of Column B and C creating the IUXz F ΔT₂SEot Delta of Column B and D creating the IUTz G FTR od Ratio of Column E divided by F The FTR od is subtracted from 2 creating the Exponent that replaces the ISI H Time@T₂S Time at the start of Zero Order Kinetics I Time@Map Time at the Maximum Acceleration Point (MAP) J Time@TEot Time at the Theoretical End of Test (TEOT) K ΔT₂SMap Delta of Column H and I creating the IUXz (and ZTM) L ΔT₂STEot Delta of Column H and J creating the IUTz M FTR Time Ration of Column K divided by L

TABLE 3 (Part A) ID OD@T2S OD@Map OD@Eot ΔT2SMap ΔT2SEot A001 3719 3707 3664 12 55 A002 3713 3704 3686 9 27 A003 3729 3720 3705 9 24 A004 3708 3696 3663 12 45 A005 3727 3715 3700 12 27 A007 3725 3718 3698 7 27 A008 3714 3693 3646 21 68 A009 3727 3716 3697 11 30 A010 3727 3714 3701 13 26 A011 3690 3676 3647 14 43 A012 3728 3716 3695 12 33 A013 3715 3690 3641 25 74 A014 3717 3708 3694 9 23 A015 3726 3718 3706 8 20 A016 3722 3715 3678 7 44 A017 3720 3707 3681 13 39 A018 3723 3709 3697 14 26 A019 3716 3695 3653 21 63 A020 3727 3716 3698 11 29 A021 3727 3720 3694 7 33 A022 3717 3700 3667 17 50 A023 3719 3706 3663 13 56 A024 3717 3702 3661 15 56 A025 3731 3727 3716 4 15 A026 3717 3705 3673 12 44 A027 3714 3698 3667 16 47 A028 3713 3696 3651 17 62 A029 3712 3691 3647 21 65 A030 3716 3695 3635 21 81 A031 3715 3704 3687 11 28 A032 3716 3710 3675 6 41 A033 3718 3704 3671 14 47 A034 3721 3705 3674 16 47 A035 3723 3715 3699 8 24 A036 3722 3710 3681 12 41 A037 3715 3700 3669 15 46 A038 3722 3707 3686 15 36 A039 3721 3712 3698 9 23 A040 3720 3706 3664 14 56 A041 3711 3695 3638 16 73 A042 3722 3709 3687 13 35 A044 3723 3709 3683 14 40 A045 3712 3697 3647 15 65 A047 3716 3697 3668 19 48 A048 3720 3708 3682 12 38 A049 3725 3711 3690 14 35 A050 3724 3712 3685 12 39 A051 3705 3688 3634 17 71 A052 3725 3714 3687 11 38 A053 3724 3717 3696 7 28 A054 3715 3701 3679 14 36 A055 3718 3684 3627 34 91 A056 3710 3689 3624 21 86 A057 3709 3701 3683 8 26 A058 3725 3710 3669 15 56 A059 3722 3712 3696 10 26 A060 3719 3712 3698 7 21 A061 3720 3708 3680 12 40 A062 3719 3701 3651 18 68 A063 3728 3715 3697 13 31 A064 3718 3707 3685 11 33 A065 3721 3704 3680 17 41 A066 3727 3717 3707 10 20 A067 3708 3689 3641 19 67 A068 3726 3712 3686 14 40 A069 3719 3715 3695 4 24 A070 3716 3705 3671 11 45 A071 3714 3696 3660 18 54 A072 3713 3693 3646 20 67 A073 3707 3686 3639 21 68 A074 3699 3684 3665 15 34 A075 3734 3730 3726 4 8 A076 3719 3704 3665 15 54 A077 3718 3694 3634 24 84 A078 3723 3707 3684 16 39 A080 3729 3712 3637 17 92 A081 3710 3694 3626 16 84 A082 3716 3703 3654 13 62 A083 3720 3710 3686 10 34 A084 3731 3721 3667 10 64 A085 3727 3704 3675 23 52 A086 3717 3699 3650 18 67 A087 3715 3694 3654 21 61 A088 3704 3681 3630 23 74 A089 3723 3714 3687 9 36 A090 3714 3685 3588 29 126 A091 3724 3710 3659 14 65 A092 3696 3657 3582 39 114 A093 3730 3716 3693 14 37 A094 3720 3708 3676 12 44 A095 3710 3689 3638 21 72 A096 3725 3717 3700 8 25 A097 3721 3713 3692 8 29 A098 3716 3696 3659 20 57 A099 3720 3712 3685 8 35 A100 3709 3685 3625 24 84 A101 3727 3715 3690 12 37 A102 3722 3708 3661 14 61 A103 3714 3693 3640 21 74 A104 3719 3705 3682 14 37 A105 3725 3706 3660 19 65 A107 3720 3707 3660 13 60 A108 3731 3723 3709 8 22 A109 3727 3711 3689 16 38 A110 3719 3693 3635 26 84 A111 3723 3701 3667 22 56 A112 3714 3695 3614 19 100 A113 3717 3702 3664 15 53 A114 3711 3687 3655 24 56 A115 3716 3697 3652 19 64 A116 3726 3717 3698 9 28 A117 3710 3688 3630 22 80 A118 3729 3721 3699 8 30 A119 3729 3716 3679 13 50 A120 3722 3713 3688 9 34 A121 3730 3722 3704 8 26 A122 3713 3688 3650 25 63 A123 3729 3721 3704 8 25 A124 3721 3712 3696 9 25 A125 3683 3668 3600 15 83 A126 3736 3723 3714 13 22 A127 3715 3703 3640 12 75 A128 3723 3714 3682 9 41 A129 3728 3715 3677 13 51 A130 3715 3700 3656 15 59 A131 3723 3711 3690 12 33 A132 3720 3700 3665 20 55 A133 3728 3706 3673 22 55 A134 3725 3696 3667 29 58 A135 3717 3703 3676 14 41 A136 3725 3712 3659 13 66 A137 3712 3691 3662 21 50 A138 3714 3691 3641 23 73 A139 3717 3700 3642 17 75 A140 3710 3690 3642 20 68 A141 3715 3698 3661 17 54 A142 3729 3719 3706 10 23 A143 3726 3709 3693 17 33 A144 3709 3693 3641 16 68 A145 3704 3688 3639 16 65 A146 3718 3706 3664 12 54 A147 3713 3698 3661 15 52 A148 3714 3701 3646 13 68 A149 3711 3692 3653 19 58 A150 3701 3678 3608 23 93 A151 3701 3668 3587 33 114 A152 3717 3706 3683 11 34 A153 3691 3669 3596 22 95 A154 3706 3690 3645 16 61 A155 3724 3703 3667 21 57 A156 3717 3711 3688 6 29 A157 3717 3702 3678 15 39 A158 3723 3715 3689 8 34 A159 3714 3696 3652 18 62 A160 3717 3690 3655 27 62 A161 3720 3713 3676 7 44 A162 3722 3706 3653 16 69 A163 3725 3715 3683 10 42 A164 3721 3712 3685 9 36 A165 3707 3693 3636 14 71 A166 3704 3683 3631 21 73 A167 3718 3712 3690 6 28 A168 3722 3700 3669 22 53 A169 3705 3694 3624 11 81 A170 3717 3704 3680 13 37 A171 3721 3699 3666 22 55 A172 3726 3719 3691 7 35 A173 3718 3708 3680 10 38 A174 3707 3692 3648 15 59 A175 3689 3671 3642 18 47 A176 3724 3711 3671 13 53 A177 3721 3710 3689 11 32 A178 3716 3700 3655 16 61 A179 3717 3707 3672 10 45 A180 3718 3706 3686 12 32 A181 3722 3703 3676 19 46 A182 3716 3706 3667 10 49 A183 3711 3703 3689 8 22 A184 3717 3705 3661 12 56 A185 3711 3694 3639 17 72 A186 3721 3675 3620 46 101 A187 3715 3704 3668 11 47 A188 3717 3703 3672 14 45 A189 3709 3689 3658 20 51 A190 3718 3709 3688 9 30 A191 3725 3717 3696 8 29 A192 3722 3714 3691 8 31 A193 3727 3718 3685 9 42 A194 3720 3710 3688 10 32 A195 3691 3667 3589 24 102 A196 3718 3707 3673 11 45 A197 3706 3692 3637 14 69 A198 3717 3707 3692 10 25 A199 3720 3705 3684 15 36 A200 3718 3709 3686 9 32 A201 3725 3713 3681 12 44 A202 3723 3713 3694 10 29 A203 3715 3704 3670 11 45 A204 3723 3713 3697 10 26 A205 3717 3706 3674 11 43 A207 3710 3702 3668 8 42 A208 3722 3708 3680 14 42 A209 3725 3709 3682 16 43 A210 3724 3714 3688 10 36 A211 3712 3694 3637 18 75 A212 3727 3711 3689 16 38 A213 3724 3705 3652 19 72 A214 3727 3715 3687 12 40 A215 3715 3703 3668 12 47 A216 3722 3707 3667 15 55 A217 3716 3695 3630 21 86 A218 3699 3665 3583 34 116 A219 3727 3716 3699 11 28 A220 3717 3704 3674 13 43 A222 3713 3704 3684 9 29 A223 3724 3715 3695 9 29 A224 3718 3703 3676 15 42 A225 3721 3707 3683 14 38

TABLE 3 (Part B) ID FTR od Time@T2S Time@Map Time@TEot ΔT2SMap ΔT2STEot FTR time FTR od A001 0.218 2211 2366 2921 155 710 0.218 0.218 A002 0.333 2279 2464 2834 185 555 0.333 0.333 A003 0.375 2329 2523 2846 194 517 0.375 0.375 A004 0.267 1975 2107 2470 132 495 0.267 0.267 A005 0.444 2166 2387 2663 221 497 0.444 0.444 A007 0.259 1838 1931 2197 93 359 0.259 0.259 A008 0.309 2160 2369 2837 209 677 0.309 0.309 A009 0.367 2391 2598 2956 207 565 0.367 0.367 A010 0.500 1716 1925 2134 209 418 0.500 0.500 A011 0.326 1788 1935 2240 147 452 0.326 0.326 A012 0.364 2233 2428 2769 195 536 0.364 0.364 A013 0.338 2409 2667 3173 258 764 0.338 0.338 A014 0.391 1701 1836 2046 135 345 0.391 0.391 A015 0.400 1715 1877 2120 162 405 0.400 0.400 A016 0.159 2233 2336 2880 103 647 0.159 0.159 A017 0.333 1728 1882 2190 154 462 0.333 0.333 A018 0.538 1862 2175 2443 313 581 0.538 0.538 A019 0.333 1756 1927 2269 171 513 0.333 0.333 A020 0.379 2535 2761 3131 226 596 0.379 0.379 A021 0.212 2151 2283 2773 132 622 0.212 0.212 A022 0.340 1900 2089 2456 189 556 0.340 0.340 A023 0.232 2251 2384 2824 133 573 0.232 0.232 A024 0.268 2522 2676 3097 154 575 0.268 0.268 A025 0.267 1708 1775 1959 67 251 0.267 0.267 A026 0.273 1611 1730 2047 119 436 0.273 0.273 A027 0.340 1537 1689 1984 152 447 0.340 0.340 A028 0.274 1780 1927 2316 147 536 0.274 0.274 A029 0.323 1839 2023 2409 184 570 0.323 0.323 A030 0.259 2051 2245 2799 194 748 0.259 0.259 A031 0.393 2107 2321 2652 214 545 0.393 0.393 A032 0.146 2584 2678 3226 94 642 0.146 0.146 A033 0.298 2251 2426 2839 175 588 0.298 0.298 A034 0.340 1909 2107 2491 198 582 0.340 0.340 A035 0.333 3037 3305 3841 268 804 0.333 0.333 A036 0.293 2211 2417 2915 206 704 0.293 0.293 A037 0.326 2173 2335 2670 162 497 0.326 0.326 A038 0.417 1543 1713 1951 170 408 0.417 0.417 A039 0.391 1572 1721 1953 149 381 0.391 0.391 A040 0.250 1959 2119 2599 160 640 0.250 0.250 A041 0.219 1993 2144 2682 151 689 0.219 0.219 A042 0.371 2660 2929 3384 269 724 0.371 0.371 A044 0.350 2657 2858 3231 201 574 0.350 0.350 A045 0.231 2175 2325 2825 150 650 0.231 0.231 A047 0.396 2197 2458 2856 261 659 0.396 0.396 A048 0.316 2535 2783 3320 248 785 0.316 0.316 A049 0.400 2004 2256 2634 252 630 0.400 0.400 A050 0.308 2193 2403 2876 210 683 0.308 0.308 A051 0.239 1745 1867 2255 122 510 0.239 0.239 A052 0.289 2073 2247 2674 174 601 0.289 0.289 A053 0.250 2239 2353 2695 114 456 0.250 0.250 A054 0.389 1816 2005 2302 189 486 0.389 0.389 A055 0.374 3127 3668 4575 541 1448 0.374 0.374 A056 0.244 2538 2728 3316 190 778 0.244 0.244 A057 0.308 2125 2263 2574 138 449 0.308 0.308 A058 0.268 4120 4529 5647 409 1527 0.268 0.268 A059 0.385 2164 2358 2668 194 504 0.385 0.385 A060 0.333 2325 2494 2832 169 507 0.333 0.333 A061 0.300 2006 2205 2669 199 663 0.300 0.300 A062 0.265 3718 4058 5002 340 1284 0.265 0.265 A063 0.419 2231 2584 3073 353 842 0.419 0.419 A064 0.333 1926 2076 2376 150 450 0.333 0.333 A065 0.415 2225 2494 2874 269 649 0.415 0.415 A066 0.500 1761 1968 2175 207 414 0.500 0.500 A067 0.284 1701 1852 2233 151 532 0.284 0.284 A068 0.350 1979 2215 2653 236 674 0.350 0.350 A069 0.167 1935 1998 2313 63 378 0.167 0.167 A070 0.244 1939 2063 2446 124 507 0.244 0.244 A071 0.333 1762 1950 2326 188 564 0.333 0.333 A072 0.299 1723 1912 2356 189 633 0.299 0.299 A073 0.309 1614 1774 2132 160 518 0.309 0.309 A074 0.441 1698 1884 2120 186 422 0.441 0.441 A075 0.500 1489 1620 1751 131 262 0.500 0.500 A076 0.278 1529 1684 2087 155 558 0.278 0.278 A077 0.286 2845 3154 3927 309 1082 0.286 0.286 A078 0.410 1867 2081 2389 214 522 0.410 0.410 A080 0.185 3548 3924 5583 376 2035 0.185 0.185 A081 0.190 2698 2853 3512 155 814 0.190 0.190 A082 0.210 1625 1744 2193 119 568 0.210 0.210 A083 0.294 1583 1692 1954 109 371 0.294 0.294 A084 0.156 3394 3647 5013 253 1619 0.156 0.156 A085 0.442 2416 2867 3436 451 1020 0.442 0.442 A086 0.269 2111 2293 2788 182 677 0.269 0.269 A087 0.344 1740 1924 2274 184 534 0.344 0.344 A088 0.311 1715 1881 2249 166 534 0.311 0.311 A089 0.250 1876 1981 2296 105 420 0.250 0.250 A090 0.230 3411 3775 4993 364 1582 0.230 0.230 A091 0.215 3897 4201 5308 304 1411 0.215 0.215 A092 0.342 1906 2151 2622 245 716 0.342 0.342 A093 0.378 2821 3197 3815 376 994 0.378 0.378 A094 0.273 2447 2600 3008 153 561 0.273 0.273 A095 0.292 1573 1726 2098 153 525 0.292 0.292 A096 0.320 1784 1913 2187 129 403 0.320 0.320 A097 0.276 1374 1479 1755 105 381 0.276 0.276 A098 0.351 1480 1655 1979 175 499 0.351 0.351 A099 0.229 1679 1770 2077 91 398 0.229 0.229 A100 0.286 1538 1705 2123 167 585 0.286 0.286 A101 0.324 2137 2344 2775 207 638 0.324 0.324 A102 0.230 2473 2657 3275 184 802 0.230 0.230 A103 0.284 1868 2069 2576 201 708 0.284 0.284 A104 0.378 2344 2732 3369 388 1025 0.378 0.378 A105 0.292 2427 2750 3532 323 1105 0.292 0.292 A107 0.217 2140 2305 2902 165 762 0.217 0.217 A108 0.364 1876 2034 2311 158 435 0.364 0.364 A109 0.421 1900 2206 2627 306 727 0.421 0.421 A110 0.310 2621 3048 4001 427 1380 0.310 0.310 A111 0.393 2064 2409 2942 345 878 0.393 0.393 A112 0.190 2000 2165 2868 165 868 0.190 0.190 A113 0.283 1699 1872 2310 173 611 0.283 0.283 A114 0.429 1838 2101 2452 263 614 0.429 0.429 A115 0.297 2091 2281 2731 190 640 0.297 0.297 A116 0.321 1571 1707 1994 136 423 0.321 0.321 A117 0.275 1691 1874 2356 183 665 0.275 0.275 A118 0.267 1835 1969 2338 134 503 0.267 0.267 A119 0.260 2118 2320 2895 202 777 0.260 0.260 A120 0.265 1833 1960 2313 127 480 0.265 0.265 A121 0.308 1825 1992 2368 167 543 0.308 0.308 A122 0.397 1674 1931 2322 257 648 0.397 0.397 A123 0.320 1669 1824 2153 155 484 0.320 0.320 A124 0.360 1627 1766 2013 139 386 0.360 0.360 A125 0.181 1485 1591 2072 106 587 0.181 0.181 A126 0.591 2476 2969 3310 493 834 0.591 0.591 A127 0.160 1935 2040 2591 105 656 0.160 0.160 A128 0.220 2485 2627 3132 142 647 0.220 0.220 A129 0.255 3083 3385 4268 302 1185 0.255 0.255 A130 0.254 3137 3330 3896 193 759 0.254 0.254 A131 0.364 1729 1930 2282 201 553 0.364 0.364 A132 0.364 2288 2601 3149 313 861 0.364 0.364 A133 0.400 2132 2531 3130 399 998 0.400 0.400 A134 0.500 3654 4285 4916 631 1262 0.500 0.500 A135 0.341 1511 1652 1924 141 413 0.341 0.341 A136 0.197 2697 2874 3596 177 899 0.197 0.197 A137 0.420 1797 1980 2233 183 436 0.420 0.420 A138 0.315 1931 2137 2585 206 654 0.315 0.315 A139 0.227 1905 2069 2629 164 724 0.227 0.227 A140 0.294 1483 1623 1959 140 476 0.294 0.294 A141 0.315 1872 2044 2418 172 546 0.315 0.315 A142 0.435 2390 2573 2811 183 421 0.435 0.435 A143 0.515 2047 2421 2773 374 726 0.515 0.515 A144 0.235 2017 2143 2553 126 536 0.235 0.235 A145 0.246 1492 1602 1939 110 447 0.246 0.246 A146 0.222 1899 2068 2660 169 761 0.222 0.222 A147 0.288 1608 1738 2059 130 451 0.288 0.288 A148 0.191 1967 2090 2610 123 643 0.191 0.191 A149 0.328 1581 1718 1999 137 418 0.328 0.328 A150 0.247 1558 1690 2092 132 534 0.247 0.247 A151 0.289 2177 2402 2954 225 777 0.289 0.289 A152 0.324 1876 2006 2278 130 402 0.324 0.324 A153 0.232 1713 1859 2343 146 630 0.232 0.232 A154 0.262 1887 2053 2520 166 633 0.262 0.262 A155 0.368 2906 3327 4049 421 1143 0.368 0.368 A156 0.207 2191 2291 2674 100 483 0.207 0.207 A157 0.385 1886 2065 2351 179 465 0.385 0.385 A158 0.235 2424 2551 2964 127 540 0.235 0.235 A159 0.290 2678 2973 3694 295 1016 0.290 0.290 A160 0.435 2160 2489 2915 329 755 0.435 0.435 A161 0.159 1674 1762 2227 88 553 0.159 0.159 A162 0.232 3480 3835 5011 355 1531 0.232 0.232 A163 0.238 2505 2697 3311 192 806 0.238 0.238 A164 0.250 2535 2718 3267 183 732 0.250 0.250 A165 0.197 2072 2189 2665 117 593 0.197 0.197 A166 0.288 1883 2051 2467 168 584 0.288 0.288 A167 0.214 2228 2321 2662 93 434 0.214 0.214 A168 0.415 2366 2847 3525 481 1159 0.415 0.415 A169 0.136 2543 2661 3412 118 869 0.136 0.136 A170 0.351 1456 1589 1835 133 379 0.351 0.351 A171 0.400 2463 2761 3208 298 745 0.400 0.400 A172 0.200 1944 2070 2574 126 630 0.200 0.200 A173 0.263 1505 1600 1866 95 361 0.263 0.263 A174 0.254 1687 1816 2194 129 507 0.254 0.254 A175 0.383 1681 1821 2047 140 366 0.383 0.383 A176 0.245 2344 2544 3159 200 815 0.245 0.245 A177 0.344 1596 1733 1995 137 399 0.344 0.344 A178 0.262 2019 2183 2644 164 625 0.262 0.262 A179 0.222 2056 2181 2619 125 563 0.222 0.222 A180 0.375 1891 2096 2438 205 547 0.375 0.375 A181 0.413 2575 2959 3505 384 930 0.413 0.413 A182 0.204 1828 1930 2328 102 500 0.204 0.204 A183 0.364 1523 1644 1856 121 333 0.364 0.364 A184 0.214 2049 2187 2693 138 644 0.214 0.214 A185 0.236 2417 2606 3217 189 800 0.236 0.236 A186 0.455 2223 2909 3729 686 1506 0.455 0.455 A187 0.234 1654 1755 2086 101 432 0.234 0.234 A188 0.311 2229 2460 2972 231 743 0.311 0.311 A189 0.392 2320 2588 3003 268 683 0.392 0.392 A190 0.300 2473 2670 3130 197 657 0.300 0.300 A191 0.276 1782 1907 2235 125 453 0.276 0.276 A192 0.258 2127 2255 2623 128 496 0.258 0.258 A193 0.214 1788 1920 2404 132 616 0.214 0.214 A194 0.313 1930 2107 2496 177 566 0.313 0.313 A195 0.235 1581 1710 2129 129 548 0.235 0.235 A196 0.244 1821 1958 2381 137 560 0.244 0.244 A197 0.203 1743 1835 2196 92 453 0.203 0.203 A198 0.400 1696 1912 2236 216 540 0.400 0.400 A199 0.417 1498 1665 1899 167 401 0.417 0.417 A200 0.281 1441 1554 1843 113 402 0.281 0.281 A201 0.273 2036 2205 2656 169 620 0.273 0.273 A202 0.345 1898 2080 2426 182 528 0.345 0.345 A203 0.244 1768 1880 2226 112 458 0.244 0.244 A204 0.385 1642 1820 2105 178 463 0.385 0.385 A205 0.256 1851 1983 2367 132 516 0.256 0.256 A207 0.190 2173 2299 2835 126 662 0.190 0.190 A208 0.333 2277 2531 3039 254 762 0.333 0.333 A209 0.372 1721 1937 2302 216 581 0.372 0.372 A210 0.278 1907 2066 2479 159 572 0.278 0.278 A211 0.240 2153 2306 2791 153 638 0.240 0.240 A212 0.421 2143 2458 2891 315 748 0.421 0.421 A213 0.264 2057 2332 3099 275 1042 0.264 0.264 A214 0.300 2116 2363 2939 247 823 0.300 0.300 A215 0.255 1982 2118 2515 136 533 0.255 0.255 A216 0.273 2799 3061 3760 262 961 0.273 0.273 A217 0.244 2021 2237 2906 216 885 0.244 0.244 A218 0.293 2319 2571 3179 252 860 0.293 0.293 A219 0.393 2098 2309 2635 211 537 0.393 0.393 A220 0.302 1803 1943 2266 140 463 0.302 0.302 A222 0.310 1705 1876 2256 171 551 0.310 0.310 A223 0.310 1593 1732 2041 139 448 0.310 0.310 A224 0.357 1649 1811 2103 162 454 0.357 0.357 A225 0.368 1655 1824 2114 169 459 0.368 0.368

Comparative Results of nATFt's and nATFz's

Results between patients in two different geographic locations (i.e., two different hospitals) were compared for correlation with each other. This comparison is expressed in Table 4 below, and includes a comparison of INR values calculated by the WHO method for each respective location, with GInr representing one location for these traditionally WHO determined values, and MInr representing values based on data obtained at the other location. The values identified as ATFz and ATFt, such as, GATFt and MATFt, and GATFz and MATFz, represent anticoagulant therapy factors derived from the expressions (1) through (9) above.

The ATFa represents an anticoagulation therapy factor derived from our method and apparatus for the expression ATFa=XR^((2-nFTR)) wherein a maximum acceleration point is obtained, and nFTR=IUX/IUT, where IUX is the change in optical density from a time prior to the MAP time (t_(<MAP) which is t_(MAP) minus some time from MAP) to the optical density at a time after the MAP time (t_(>MAP) which is t_(MAP) plus some time from MAP); and wherein IUT=the change in optical density at the time t₁ to the optical density measured at time t_(EOT), where time t_(EOT) is the end of the test (EOT). The (IUX) represents the fibrinogen (FBG) for MAP (−a number of seconds) to MAP (+a number of seconds) (that is the fibrinogen (FBG) converted from t_(<MAP) to t_(>MAP) on FIG. 2) The (IUT) represents fibrinogen converted from c₁ to c_(EOT) (that is the fibrinogen converted from t₁ to t_(EOT), see FIG. 2). The XR for the ATFa expression is XR=TX/MNTX, which is the ratio of time to map (TX) by the mean normal time to map of 20 presumed “normal” patients.

TABLE 4 COMPARATIVE RESULTS FOR ATFt and ATFz Std. Comparison n r m b Error Ng Lassen GInr vs. 129 0.996 0.891 0.148 0.082 6/129 = delta <= 0.4 5@96.1% GATFa 4.7% delta <= 0.7 2@98.4% mismatches GInr vs. 129 0.975 1.014 −0.016 0.215 15/129 = delta <= 0.4 9@93% GATFz 11.6% delta <= 0.7 3@97.7% mismatches GInr vs. 129 0.971 0.895 0.332 0.232 26/129 = delta <= 0.4 18@86.0% GATFt 20.2% delta <= 0.7 2@98.4% mismatches MInr vs. 129 0.996 0.943 0.082 0.094 18/129 = delta <= 0.4 15@88.4% MATFa 14.0% delta <= 0.7 5@96.1% mismatches MInr vs. 129 0.985 0.993 −0.058 0.177 2/129 = delta <= 0.4 0@100% MATFz 1.6% delta <= 0.7 0@100% mismatches MInr vs. 129 0.981 0.851 0.420 0.200 8/129 = delta <= 0.4 6@95.3 MATFt 6.2% delta <= 0.7 2@98.4% mismatches

A comparison of combined location data is shown in Table 5, below. The sample size was 217.

TABLE 5 STATISTICAL SUMMARY OF MHTL DATA Com- Std. parison n r m b Error Ng Lassen Inr vs 217 0.984 1.006 0.011 0.215 30/217 = delta <= 0.4 ATFa 13.8% 16@92.6% mismatches delta <= 0.7 1@99.5% Inr vs. 217 0.984 1.002 0.120 0.214 26/217 = delta <= 0.4 ATFz 12.0% 18@91.7% mismatched delta <= 0.7 3@98.6% Inr vs. 217 0.984 0.900 0.482 1.218 45/217 = delta <= 0.4 ATFt 20.7% 43@80.2% mismatches delta <= 0.7 6@97.2%

Comparative results were also calculated for the ATFt which includes the lag phase fibrinogen, in accordance with the IULz, using the expression (5.1) for the TEOT value. Table 6 below provides the values for the ATFz, ATFt, and the ATFt2 (which is obtained from expression 5.1 using the IULz).

TABLE 6 ID INR INRz ATFt ATFt2 A001 3.1 2.9 2.4 2.6 A002 3.3 2.9 2.4 2.6 A003 3.3 2.9 2.4 2.6 A004 2.1 2.3 1.8 2.0 A005 2.9 2.6 2.1 2.3 A007 2.1 2.0 1.5 1.6 A008 2.8 2.8 2.3 2.5 A009 3.4 3.1 2.6 2.8 A010 1.9 1.8 1.3 1.5 A011 2.1 1.9 1.5 1.6 A012 3.2 2.8 2.3 2.5 A013 3.5 3.3 2.8 3.0 A014 1.8 1.7 1.3 1.4 A015 1.9 1.8 1.3 1.5 A016 3.2 2.9 2.4 2.6 A017 1.8 1.9 1.4 1.6 A018 2.2 2.1 1.7 1.8 A019 1.8 1.9 1.5 1.6 A020 3.5 3.4 2.9 3.2 A021 2.8 2.7 2.2 2.4 A022 2.2 2.2 1.7 1.9 A023 3.2 2.9 2.3 2.5 A024 3.7 3.5 2.9 3.1 A025 1.8 1.7 1.2 1.4 A026 1.6 1.6 1.2 1.4 A027 1.5 1.5 1.1 1.3 A028 1.9 2.0 1.5 1.7 A029 2.1 2.1 1.6 1.8 A030 2.6 2.6 2.1 2.3 A031 2.7 2.5 2.1 2.3 A032 4.1 3.8 3.1 3.3 A033 2.9 2.9 2.4 2.6 A034 2.2 2.2 1.7 1.9 A035 4.9 4.7 4.3 4.7 A036 3.2 2.9 2.4 2.6 A037 2.5 2.7 2.1 2.4 A038 1.6 1.6 1.1 1.2 A039 1.4 1.6 1.1 1.3 A040 2.4 2.4 1.9 2.1 A041 2.3 2.4 2.0 2.2 A042 4.1 3.8 3.3 3.6 A044 4.2 3.7 3.2 3.4 A045 2.7 2.8 2.3 2.5 A047 2.8 2.8 2.3 2.5 A048 3.9 3.6 3.1 3.3 A049 2.6 2.4 1.9 2.1 A050 2.8 2.8 2.3 2.5 A051 1.9 1.9 1.4 1.6 A052 2.8 2.6 2.0 2.2 A053 3.0 2.8 2.2 2.4 A054 2.1 2.0 1.5 1.7 A055 5.6 5.4 5.3 5.6 A056 3.6 3.7 3.1 3.4 A057 2.8 2.6 2.0 2.2 A058 8.5 8.7 8.6 9.1 A059 2.9 2.6 2.1 2.3 A060 3.5 3.0 2.4 2.6 A061 2.4 2.5 2.0 2.1 A062 7.0 7.2 6.8 7.3 A063 3.0 3.0 2.5 2.7 A064 2.2 2.2 1.7 1.9 A065 2.6 2.8 2.4 2.6 A066 2.0 1.9 1.4 1.6 A067 1.8 1.8 1.4 1.6 A068 2.6 2.4 1.9 2.1 A069 2.4 2.2 1.6 1.8 A070 2.4 2.3 1.7 1.9 A071 1.9 2.0 1.5 1.7 A072 1.8 1.9 1.5 1.6 A073 1.5 1.7 1.3 1.4 A074 1.7 1.8 1.3 1.5 A075 1.6 1.4 1.0 1.1 A076 1.4 1.6 1.2 1.3 A077 4.5 4.6 4.1 4.4 A078 2.2 2.1 1.6 1.8 A080 7.3 7.4 7.3 7.6 A081 3.8 4.2 3.5 3.8 A082 1.6 1.7 1.3 1.5 A083 1.6 1.6 1.1 1.3 A084 6.7 6.7 6.3 6.6 A085 3.3 3.4 3.1 3.3 A086 2.8 2.7 2.2 2.4 A087 1.8 1.9 1.5 1.6 A088 1.7 1.9 1.4 1.6 A089 2.3 2.1 1.6 1.7 A090 6.3 6.6 6.3 6.7 A091 7.6 8.1 7.6 8.1 A092 1.9 2.3 1.8 2.0 A093 4.9 4.3 4.0 4.2 A094 3.2 3.3 2.7 2.9 A095 1.5 1.6 1.2 1.4 A096 2.3 1.9 1.4 1.6 A097 1.3 1.3 0.9 1.0 A098 1.4 1.5 1.1 1.2 A099 1.8 1.7 1.3 1.4 A100 1.4 1.6 1.2 1.3 A101 2.7 2.7 2.2 2.4 A102 3.8 3.6 3.0 3.2 A103 2.0 2.2 1.8 1.9 A104 3.2 3.3 2.9 3.2 A105 3.7 3.6 3.2 3.4 A107 2.9 2.8 2.3 2.5 A108 2.1 2.1 1.6 1.8 A109 2.2 2.3 1.8 2.0 A110 3.9 4.2 3.9 4.1 A111 2.5 2.7 2.2 2.4 A112 2.5 2.5 2.1 2.3 A113 1.9 1.9 1.4 1.6 A114 2.1 2.1 1.7 1.8 A115 2.4 2.6 2.1 2.3 A116 1.7 1.6 1.2 1.3 A117 1.6 1.9 1.5 1.6 A118 2.1 2.1 1.6 1.7 A119 3.0 2.7 2.3 2.4 A120 2.1 2.0 1.6 1.7 A121 2.2 2.1 1.6 1.7 A122 1.7 1.9 1.4 1.6 A123 1.8 1.8 1.3 1.5 A124 1.8 1.7 1.2 1.3 A125 1.4 1.4 1.1 1.3 A126 3.7 3.2 3.0 3.3 A127 2.4 2.3 1.8 2.0 A128 3.8 3.5 2.9 3.1 A129 5.3 5.3 4.8 5.3 A130 4.7 5.2 4.5 4.9 A131 1.7 1.9 1.5 1.6 A132 2.8 3.1 2.7 2.9 A133 2.6 2.9 2.5 2.7 A134 6.6 6.0 6.6 7.1 A135 1.5 1.5 1.1 1.2 A136 4.3 4.2 3.6 3.8 A137 1.9 1.9 1.5 1.6 A138 2.0 2.3 1.8 2.0 A139 2.1 2.3 1.8 2.0 A140 1.3 1.5 1.1 1.2 A141 2.2 2.1 1.7 1.8 A142 3.4 2.9 2.5 2.7 A143 2.5 2.5 2.1 2.3 A144 2.5 2.4 1.9 2.1 A145 1.4 1.4 1.1 1.2 A146 2.3 2.3 1.9 2.0 A147 1.7 1.6 1.2 1.4 A148 2.3 2.4 1.9 2.1 A149 1.6 1.6 1.2 1.3 A150 1.6 1.6 1.2 1.3 A151 2.8 2.9 2.4 2.6 A152 2.2 2.1 1.6 1.7 A153 1.8 1.9 1.5 1.6 A154 2.2 2.2 1.7 1.9 A155 4.8 4.6 4.3 4.7 A156 2.9 2.8 2.2 2.4 A157 2.1 2.1 1.6 1.8 A158 3.6 3.3 2.6 2.8 A159 3.9 4.1 3.6 3.9 A160 2.7 2.8 2.3 2.5 A161 1.7 1.8 1.4 1.5 A162 6.6 6.8 6.4 6.9 A163 3.9 3.6 3.1 3.3 A164 4.0 3.6 3.0 3.3 A165 2.7 2.6 2.0 2.2 A166 2.2 2.2 1.7 1.9 A167 2.9 2.8 2.2 2.4 A168 3.6 3.5 3.1 3.3 A169 4.1 3.8 3.2 3.4 A170 1.4 1.4 1.0 1.1 A171 3.4 3.3 2.9 3.1 A172 2.5 2.3 1.8 2.0 A173 1.6 1.4 1.0 1.1 A174 1.8 1.8 1.4 1.5 A175 1.8 1.7 1.3 1.4 A176 3.4 3.3 2.7 2.9 A177 1.7 1.6 1.2 1.3 A178 2.3 2.5 2.0 2.1 A179 2.6 2.5 2.0 2.2 A180 2.3 2.2 1.7 1.9 A181 3.5 3.7 3.3 3.6 A182 2.1 2.0 1.6 1.7 A183 1.5 1.5 1.0 1.2 A184 2.6 2.5 2.0 2.2 A185 3.3 3.4 2.9 3.1 A186 3.1 3.5 3.1 3.3 A187 1.8 1.7 1.3 1.4 A188 3.1 2.9 2.4 2.6 A189 3.0 3.0 2.6 2.8 A190 3.6 3.4 2.8 3.1 A191 2.0 1.9 1.5 1.6 A192 2.7 2.6 2.1 2.3 A193 2.1 2.0 1.6 1.7 A194 2.2 2.3 1.8 2.0 A195 1.4 1.6 1.2 1.4 A196 2.0 2.1 1.6 1.8 A197 1.8 1.9 1.4 1.5 A198 2.0 1.9 1.4 1.5 A199 1.5 1.5 1.0 1.2 A200 1.4 1.4 1.0 1.1 A201 2.6 2.5 2.0 2.2 A202 2.5 2.2 1.7 1.9 A203 2.0 1.9 1.4 1.6 A204 1.8 1.7 1.3 1.4 A205 1.9 2.1 1.6 1.8 A207 2.7 2.8 2.3 2.5 A208 3.0 3.0 2.5 2.8 A209 1.9 1.9 1.5 1.6 A210 2.4 2.2 1.7 1.9 A211 2.9 2.7 2.2 2.4 A212 2.8 2.7 2.3 2.5 A213 2.7 2.8 2.3 2.5 A214 2.8 2.8 2.3 2.5 A215 2.5 2.3 1.8 2.0 A216 4.1 4.4 3.9 4.2 A217 2.3 2.6 2.2 2.3 A218 2.9 3.2 2.7 3.0 A219 2.7 2.5 2.0 2.2 A220 2.0 2.0 1.5 1.7 A222 2.0 1.9 1.4 1.6 A223 1.7 1.6 1.2 1.4 A224 1.6 1.7 1.3 1.4 A225 1.8 1.7 1.3 1.4

Table 7 represents a comparison of the data from Table 6.

TABLE 7 “r” “m” “b” StdErr StdDev INR INRz 0.988 0.988 0.059 0.190 1.201 vs ATFt 0.984 0.966 0.568 0.215 1.238 ATFt2 0.983 0.913 0.504 0.219 1.257 ATFt ATFt2 1.000 0.946 −0.068 0.022 1.264 vs

Table 8 provides comparative data for the anticoagulant therapy factors, similar to Table 2, but using the ATFt2 method from expressions (4) and (5.1) for corresponding GINRt2 and MINRt2 values.

TABLE 8 ID AINR GINR GINRa GINRz GINRt2 MINR MINRa MINRz MINRt2 U0800 2.0 2.0 2.0 2.0 1.7 2.1 2.1 2.2 2.1 U7440 2.6 3.0 3.0 2.9 2.9 3.0 3.0 2.8 3.4 U7443 2.0 2.0 2.0 2.0 1.8 2.1 2.2 2.1 1.8 U7458 1.4 1.4 1.4 1.4 1.2 1.4 1.4 1.3 1.3 U7465 9.7 7.4 8.1 6.6 7.9 7.1 7.5 8.1 7.8 U7469 1.1 1.1 1.1 1.1 0.9 1.2 1.1 1.1 1.0 U7470 3.2 3.4 3.6 3.4 3.2 3.6 3.7 3.8 3.8 U8080 3.1 3.6 3.6 3.3 3.6 3.3 3.3 3.5 3.4 U8087 1.9 1.9 1.9 1.8 1.6 1.9 1.9 1.9 1.7 U8092 1.7 1.7 1.8 1.7 1.6 1.9 1.9 1.9 1.6 U3050 2.7 2.8 3.1 2.6 2.2 2.3 2.3 2.3 2.0 U3077 1.3 1.4 1.4 1.4 1.1 1.3 1.3 1.3 1.2 U3083 1.6 1.6 1.6 1.6 1.3 1.6 1.7 1.6 1.4 U8210 2.6 2.9 3.0 2.8 2.7 2.7 2.8 2.8 2.6 U8221 3.2 3.7 4.0 3.7 3.4 3.5 3.5 3.3 3.6 U3408 1.1 1.2 1.2 1.2 0.9 1.1 1.0 1.0 0.9 U3453 1.1 1.2 1.2 1.2 1.0 1.2 1.2 1.2 1.0 U3457 2.2 2.3 2.4 2.2 1.9 2.1 2.3 2.2 1.8 U3395 2.7 3.2 3.5 3.2 2.7 2.8 2.9 2.5 2.3 U3398 1.5 1.7 1.8 1.8 1.5 1.6 1.6 1.6 1.5 U3456 1.1 1.0 1.0 1.0 0.8 1.0 1.0 1.0 0.9 U3459 2.9 2.6 2.8 2.6 2.2 2.4 2.5 2.5 2.0 U0415 0.9 0.9 0.9 0.9 0.8 0.9 1.0 1.0 0.8 U0432 1.8 1.5 1.5 1.5 1.3 1.4 1.4 1.4 1.3 U0436 2.4 2.4 2.6 2.3 2.1 2.4 2.4 2.4 2.2 U0438 3.9 3.7 4.2 3.7 3.2 3.8 4.2 3.9 3.6 U0439 2.3 2.2 2.3 2.1 1.8 2.3 2.3 2.2 2.0 U0440 5.8 4.8 5.4 5.2 4.4 4.6 4.8 4.3 5.2 U0441 4.5 4.9 5.6 6.0 5.0 4.4 4.7 4.7 5.4 U0442 1.8 1.7 1.8 1.7 1.5 1.8 1.8 1.8 1.6 U3724 2.7 2.4 2.5 2.4 2.0 2.6 2.7 2.6 2.3 U0849 2.4 2.3 2.4 2.1 1.8 2.3 2.4 2.2 2.0 U0860 1.0 1.0 1.0 1.0 0.8 1.0 1.0 1.0 0.9 U0861 2.8 2.9 3.0 2.8 2.6 3.0 3.0 2.9 3.0 U0863 1.7 1.7 1.7 1.7 1.7 1.7 1.8 1.8 1.8 U0875 2.2 2.0 2.2 2.1 1.6 2.0 2.0 2.0 1.7 U0843 1.4 1.4 1.4 1.4 1.2 1.4 1.5 1.5 1.3 U0848 1.3 1.4 1.4 1.4 1.2 1.3 1.4 1.4 1.2 U0855 1.3 1.3 1.3 1.3 1.2 1.2 1.2 1.2 1.3 U0867 3.2 2.9 3.2 2.8 2.5 3.0 3.1 3.0 2.9 U1201 1.9 1.9 2.0 1.9 1.7 1.8 1.8 1.9 1.8 U1202 1.3 1.3 1.3 1.3 1.2 1.4 1.4 1.4 1.2 U1205 1.6 1.8 1.9 1.8 1.6 1.9 1.9 1.8 1.7 U1207 1.9 1.9 2.0 1.8 1.5 1.9 1.9 1.7 1.7 U1230 1.3 1.4 1.5 1.4 1.3 1.4 1.5 1.5 1.5 U1198 2.2 2.1 2.2 2.1 1.9 2.0 2.0 2.0 2.3 U1199 2.8 3.3 3.6 3.1 2.8 3.2 3.2 2.8 3.3 U1218 3.0 2.6 2.9 2.9 2.7 2.8 3.1 3.1 3.2 U1225 2.2 2.3 2.3 2.1 1.9 2.6 2.4 2.2 2.2 U1575 1.4 1.3 1.3 1.3 1.4 1.4 1.4 1.4 1.4 U1579 1.5 1.7 1.7 1.7 1.5 1.8 1.8 1.7 1.5 U1649 0.9 0.8 0.8 0.8 0.8 0.9 0.9 0.9 0.8 U1576 2.2 2.1 2.1 2.1 2.1 2.3 2.3 2.3 2.2 U1581 1.7 1.7 1.7 1.8 1.9 1.7 1.8 1.8 1.7 U1599 2.0 1.7 1.8 1.8 2.0 2.0 2.1 2.1 2.0 U1600 3.5 3.2 3.4 3.4 3.7 3.9 4.2 3.5 3.7 U4471 1.5 1.6 1.7 1.6 1.5 1.7 1.7 1.7 1.7 U4757 2.0 2.1 2.1 2.0 1.8 2.0 2.0 2.1 2.0 U4767 2.6 2.4 2.5 2.6 2.0 2.6 2.6 2.5 2.3 U4772 2.5 2.7 2.8 2.5 2.6 2.8 2.8 2.9 2.5 U4801 1.3 1.4 1.4 1.4 1.2 1.5 1.5 1.4 1.2 U4737 2.9 2.6 2.8 2.7 2.3 2.7 2.9 2.8 2.5 U4752 1.4 1.5 1.6 1.5 1.3 1.5 1.5 1.5 1.4 U5133 0.9 0.9 0.9 0.9 0.7 1.0 1.0 1.0 0.8 U5173 1.1 1.2 1.2 1.2 1.1 1.2 1.2 1.2 1.0 U5175 1.7 1.8 1.9 1.8 1.7 1.9 1.9 1.9 1.7 U5178 2.3 2.2 2.3 2.1 1.9 2.6 2.9 2.8 2.0 U5183 2.9 2.6 2.8 2.6 2.3 3.6 3.9 3.7 3.0 U5158 5.5 5.1 5.9 5.7 5.8 6.0 6.6 7.1 7.0 U5169 2.6 2.9 3.2 3.2 3.2 3.2 3.4 3.6 3.7 U5190 2.8 2.7 2.8 2.9 2.8 3.2 3.4 3.5 3.2 U5193 3.1 3.0 3.1 3.0 2.9 3.6 3.7 3.7 3.4 U5589 1.6 1.8 1.9 1.8 1.6 1.9 2.0 1.8 1.5 U5592 1.1 1.2 1.2 1.2 1.1 1.4 1.3 1.3 1.4 U5593 1.7 1.8 1.9 1.8 1.6 1.8 1.9 1.8 1.7 U5565 2.7 3.2 3.3 3.3 3.1 3.5 3.5 3.6 3.5 U5591 2.0 2.2 2.3 2.3 2.1 2.3 2.3 2.1 2.3 U5594 2.3 2.6 2.8 2.8 2.8 2.8 2.8 3.0 3.0 U5597 3.3 3.3 3.6 3.6 3.1 4.1 4.0 4.3 4.0 U5993 1.0 0.9 0.9 0.9 0.8 1.0 1.0 1.0 0.8 U6017 1.0 0.9 1.0 1.0 0.8 0.9 0.9 0.9 0.8 U6056 1.0 1.0 1.0 1.0 0.9 1.0 1.0 1.0 0.9 U5992 1.4 1.4 1.4 1.4 1.3 1.3 1.4 1.4 1.3 U6047 2.3 2.3 2.4 2.3 2.0 2.2 2.3 2.3 2.2 U6060 1.9 2.1 2.2 2.2 2.0 2.3 2.0 2.0 2.1 U6065 3.1 2.8 2.9 2.8 2.7 3.0 3.1 2.9 2.8 U6928 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.1 U6929 1.2 1.2 1.2 1.2 1.1 1.2 1.2 1.2 1.0 U6951 1.5 1.5 1.5 1.5 1.5 1.6 1.7 1.6 1.4 U6977 1.3 1.3 1.3 1.3 1.2 1.3 1.4 1.4 1.1 U6936 2.4 2.5 2.4 2.6 3.2 2.6 2.6 2.7 2.6 U6938 2.1 2.1 2.1 2.2 2.3 2.3 2.3 2.3 2.3 U6972 2.4 2.4 2.5 2.4 2.5 2.8 2.8 2.8 2.5 U6987 5.1 4.5 4.4 5.0 5.5 5.7 5.4 5.7 7.0 U7316 1.2 1.1 1.1 1.1 1.1 1.3 1.3 1.3 1.1 U7321 1.5 1.4 1.4 1.4 1.5 1.6 1.6 1.6 1.5 U7324 1.3 1.2 1.3 1.2 1.2 1.4 1.4 1.4 1.2 U7317 2.0 1.6 1.7 1.7 1.6 1.9 1.9 1.8 1.6 U7318 2.8 2.7 2.9 2.9 2.6 3.3 3.4 3.3 2.7 U7320 2.0 1.9 1.9 1.9 2.2 2.0 2.1 2.1 2.2 U7322 1.8 1.7 1.7 1.7 1.5 1.7 1.8 1.7 1.4 U7708 1.6 1.6 1.6 1.6 1.6 1.7 1.7 1.7 1.7 U7713 1.4 1.6 1.6 1.6 1.5 1.6 1.6 1.6 1.5 U7727 1.7 1.7 1.7 1.8 1.7 1.9 1.9 1.9 1.9 U7794 1.9 1.8 1.9 1.8 1.6 1.7 1.8 1.7 1.6 U7707 2.2 2.2 2.3 2.3 2.3 2.3 2.3 2.3 2.2 U7710 2.3 2.5 2.6 2.7 2.8 2.7 2.9 3.0 3.0 U7724 2.4 2.4 2.5 2.6 2.7 2.7 2.7 2.8 2.9 U7738 2.4 2.3 2.4 2.5 2.2 2.4 2.5 2.6 2.3 U8559 1.6 1.4 1.4 1.4 1.3 1.6 1.7 1.6 1.3 U8570 1.2 1.2 1.2 1.2 1.3 1.2 1.2 1.2 1.3 U8575 0.9 0.8 0.8 0.8 0.8 0.9 0.9 0.9 0.8 U8555 2.6 2.4 2.5 2.6 2.6 2.9 3.1 3.0 2.6 U8558 2.3 2.2 2.3 2.3 2.2 2.3 2.3 2.4 2.4 U8563 2.2 2.3 2.3 2.4 2.3 2.4 2.4 2.5 2.5 U9031 2.1 2.4 2.3 2.3 2.5 2.6 2.4 2.3 2.4 U9032 1.7 1.7 1.7 1.7 1.6 1.9 1.9 1.7 1.5 U9040 1.4 1.4 1.4 1.4 1.2 1.4 1.4 1.3 1.1 U9034 3.0 2.9 2.8 3.0 4.0 3.4 3.4 3.5 3.8 U9039 2.7 3.0 3.2 3.1 3.1 3.2 3.2 3.2 3.3 U9049 3.5 3.3 3.5 3.5 3.5 3.6 3.8 3.6 3.7 U9055 2.4 2.1 2.1 2.2 2.1 2.4 2.4 2.4 2.1 U0048 1.8 1.8 1.8 1.8 1.7 1.9 2.0 2.0 1.8 U0050 1.8 1.7 1.8 1.8 1.7 1.9 2.0 2.0 1.7 U0056 1.6 1.5 1.5 1.5 1.4 1.8 1.8 1.7 1.5 U0047 2.1 1.7 1.8 1.8 1.6 2.0 2.1 2.0 1.7 U0058 3.2 2.8 2.9 3.0 3.0 3.3 3.4 3.2 3.3 U0060 2.2 2.1 2.1 2.2 2.1 2.2 2.2 2.2 2.3 U0062 2.8 2.6 2.7 2.8 2.7 3.0 3.2 3.2 2.9

TABLE 9 COMPARATIVE RESULTS Comparison on n r m b Std. Error Ng Lassen GInr vs 129 0.997 0.879 0.163 0.079 7/129 = Delta <= 0.4|5 @ 96.1% GATFa 5.4% Delta <= 0.7|2 @ 98.4% GInr vs 129 0.986 0.948 0.078 0.162 3/129 = Delta <= 0.4|4 @ 96.9% GATFz 2.3% Delta <= 0.7|2 @ 98.4% GInr vs 129 0.974 0.935 0.413 0.221 20/129 = Delta <= 0.4|16 @ 87.6% GATFt2 15.5% Delta <= 0.7|4 @ 96.9% MInr vs 129 0.996 0.921 0.122 0.092 9/129 = Delta <= 0.4|2 @ 98.4% MATFa 7.0% Delta <= 0.7|0 @ 100.0% MInr vs 129 0.989 0.908 0.190 0.155 7/129 = Delta <= 0.4|4 @ 96.9% MATFz 5.4% Delta <= 0.7|2 @ 98.4% MInr vs 129 0.983 0.893 0.491 0.193 8/129 = Delta <= 0.4|13 @ 89.9% MATFt2 6.2% Delta <= 0.7|4 @ 96.9%

Table 9 provides comparative data for the ATFa, ATFz and ATFt2 and INR values calculated by the WHO method for each respective location, with GInr representing one location for these traditionally WHO determined values, and MInr representing values based on data obtained at the other location. The values identified as ATFz and ATFt2, such as, GATFt2 and MATFt2, and GATFz and MATFz, represent anticoagulant therapy factors derived from the expressions (1) through (9) above, inclusive of expressions (5.1) and (8.1).

Further comparative results are provided in Table 10 to illustrate the effect of prothrombin time (PT) on INR values. Table 10 provides a comparison based on data from Table 3, and provides INR values for PT's of PT=PT (under the heading “INR”), PT=PT+0.5 (under the heading “+0.5”), PT=PT+1.0 (under the heading “+1.0”), PT=PT+1.5 (under the heading “+1.5”), and PT=+2.0 (under the heading “+2.0”). The new anticoagulation therapy factor (ATFt2) was compared with the WHO method for determining ATF. The WHO method utilizes the mean prothrombin time of 20 presumed normal patients. The thromboplastin reagents list MNPT “expected ranges” listed in the accompanying thromboplastin-reagent (Tp) brochures. These brochures acknowledge that MNPT differences are inevitable because of variations in the 20 “normal donor” populations. Geometric, rather than arithmetic mean calculation limits MNPT variation somewhat, but simulated 0.5 second incremented increases over a total 2.5 second range, show ever-increasing INR differences notably at higher INR levels. To exemplify this, Table 10 shows these changes with Thromboplastin C Plus (which has a manufacturer's reported ISI=1.74 and MNPT=9.89 seconds) in POTENS+.

TABLE 10 ID PT INR +0.5 +1.0 +1.5 +2.0 WEC 9.8 1.0 0.9 0.8 0.8 0.7 A095 12.5 1.5 1.4 1.3 1.2 1.1 A191 14.8 2.0 1.9 1.7 1.6 1.5 A112 16.9 2.5 2.3 2.2 2.0 1.8 A208 18.6 3.0 2.8 2.5 2.3 2.2 A020 20.3 3.5 3.2 3.0 2.7 2.5 A164 21.9 4.0 3.7 3.4 3.1 2.9 A093 24.5 4.9 4.5 4.1 3.8 3.5 A055 26.5 5.6 5.1 4.7 4.4 4.0 A090 28.5 6.3 5.8 5.3 4.9 4.6 R091 32.2 7.8 7.2 6.6 6.1 5.7 A058 33.8 8.5 7.8 7.2 6.6 6.2

Since the in-house determined MNPT would continue with that Tp lot, intralaboratory results would be relatively unaffected. However, between laboratory INR agreements, or interlab results, are compromised. As a denominator, considering the expression used to derive the MNPT, such as expression (B), above, MNPT is, of course, less problematic for INRs than the exponent, ISI. Comparative results, showing interlab results, are provided in Table 11. ATFt is seen to be numerically equal to WHO/INRs determined in both analytical instruments, namely, the MDA-Electra 9000C and the POTENS+. Identical computer bits derived in POTENS+ from the absorbances creating the thrombin-fibrinogen-fibrin clotting curve are used for the POTENS+WHO/INR and ATFt (NO ISI, NO MNPT) determinations. MNPT is, of course, still necessary for the WHO method. For ATFt, Zero Order Kinetics Line's slope is extended in both directions to intersect with the Tp-plasma baseline and the absorbance at total fibrin formation. The sum of this interval and the time from the Tp injection to the beginning of Zero Order Kinetics (T₂S) is Value 1. Value 2 is T₂S/100e. “e” is the Natural Logarithm, base 2.71828. ATFt=(Value 1)*(Value 2), in accordance with expression (4) herein (and the expression (8.1) for ATFt2).

Table 11 provides statistical comparisons for results obtained using two POTENS+coagulometers (one designated as GINR and another designated as MINR), and using a Bio Merieux MDA-180 coagulometer (designated as AINR). The POTENS+, WHO/INRs, INR_(z)s, and ATFts and the MDA-180 (AINR) WHO/INRs are compared. Statistical data and Bland-Altman plot data demonstrate that the new anticoagulant therapy factor ATFt may replace WHO/INR and provide results which are within the parameters of traditional therapeutic or reference ranges.

TABLE 11 “r” “m” “b” StdErr StdDev mY mX My/mX AINR GINR 0.937 0.872 0.290 0.388 1.148 2.169 2.155 1.007 vs GATFz 0.941 1.119 −0.208 0.378 1.022 2.169 2.124 1.021 GATFt2 0.951 1.003 0.146 0.343 1.081 2.169 2.016 1.076 MINR 0.950 1.018 −0.126 0.349 1.070 2.169 2.253 0.963 MATFz 0.943 1.020 −0.040 0.371 1.065 2.169 2.167 1.001 MATFt2 0.937 0.872 0.290 0.388 1.148 2.169 2.155 1.007 MINR GINR 0.971 1.036 0.039 0.247 1.001 2.253 2.136 1.055 vs MINRz GINRz 0.984 1.082 −0.132 0.186 0.978 2.167 2.124 1.020 vs MINRt2 GINRt2 0.979 1.110 −0.083 0.242 1.123 2.155 2.016 1.069 vs

The linear regression analysis expression y=mx+b, when solved for the slope, m, is expressed as (y−b)/x. This is biased, so the expression is y/x is when b is equal to zero. The comparison in Table 11, above, provides comparative data for mean y (mY) and mean x (mX) values, including the slope mY/mX. The use of mY/mX is used to provide comparative results.

In another embodiment, an article may be provided to derive an anticoagulant therapy factor (ATF). The article may comprise stored instructions on a storage media which can be read and processed with a processor. For example, the computer may be provided with a stored set of instructions, or chip, which is programmed to determine a new ATF for the spectral data obtained from the coagulation activity of a sample. For example, the computer chip may be preprogrammed with a set of instructions for cooperating with the output of a photodetection device, such as, the device shown and described in FIG. 1, which provides electrical data to said computer processor and/or storage device as a function of the optical density for a sample being analyzed. The chip may be employed in, or used with, an apparatus having input means and storage means for storing data. The set of instructions on the chip includes instructions for carrying out the steps of determining one or more anticoagulant therapy factors based on the expressions (1) through (9), inclusive of expressions (5.1) and (8.1).

According to alternate embodiments, methods for determining an anticoagulant therapy factor are provided to derive an INR. The customary classical INR (also referred to herein as INR_(m)) has been the laboratory standard of care for monitoring oral anticoagulant therapies, such as, for example, coumarin therapy, for 25 years. However, the classical INR (INRm) which is discussed in the background, above, is cumbersome, and suffers from exponential inaccuracies. According to an alternate embodiment, the exponent-derived INR_(m) (that is, the manufacturer's INR) may be supplantable by carrying out a clotting reaction and recording absorbance values over time intervals. The alternate INR (INRn) may be determined by computing the representative area of a trapezoid formed within the clotting curve absorbance, as determined by the absorbance values for the clotting reaction of a patient sample. According to preferred embodiments, the trapezoidal area is provided to approximate area under the clotting curve. According to this embodiment, the ISI and MNPT are eliminated. The sample of a person's blood or blood component is obtained and reacted with the coagulant, such as thromboplastin C, and the corresponding time and absorbance values for the clotting reaction of the sample are recorded.

The INRn may be used to determine and regulate treatment for a patient, including administration of anticoagulant therapy, and other blood therapy applications. According to one embodiment of the method, obtaining values for an area in connection with a blood clotting analysis is used to derive a corresponding INR value (INRn) (e.g., a value that may be used as the INR value is used). For example, according to a preferred embodiment, an Area T, which may be made up of two sides S1 and S2, an upper base S3 and a lower base S4, may be derived to generate an INR value, INRn. An INRn value may be derived from clotting curve data, wherein one or more locations along the clotting curve may be used to determine values corresponding to a designated area, as in accordance with preferred embodiments, may be represented by a trapezoidal area, such as that area represented by Area T. According to a preferred embodiment, the area is a two dimensional planar location, and, for example, may comprise a designated area located in a quadrant of an ordinate and abscissa corresponding with clotting curve time and absorbance values. The clotting curve and absorbance values, preferably, may be obtained with the use of a photodetection apparatus, and a computer that records the electrical output of the detection components. For example, a linear-output photo-optical coagulometer may be used to obtain optically responsive signal data from the sample, as the clotting reaction takes place. This reaction and absorbance data collection may be conducted as described herein in conjunction with the use of a coagulometer, such as the instrument illustrated in FIG. 1, or other suitable absorbance measuring device. Preferred devices are described herein and may be configured with the instructions to provide the INRn.

As illustrated in connection with FIG. 6, a clotting curve is shown. An Area T is identified in the first quadrant where the clotting curve of a coagulation reaction is illustrated. The Area T derivation may be used to derive a corresponding INRn value for the patient sample that generated the information represented by the clotting curve. The INRn values obtained by the method and apparatus are useful in determining the treatment course for an individual, based on the INRn value.

According to a preferred embodiment, the INRn may be expressed with the following formulae:

INRn=(Area T)*MUL  (10)

The MUL is a multiplier that is based on two relationships that are addressed by the multiplier. MUL relates the sampling rate of the instrument and the pixel parity of the x-y axis. The instrument used to measure the optical changes in the sample generates values, and preferably, the values, or signals are taken at a particular frequency. For example, a preferred sampling rate for the clotting curve reaction of a patient blood or blood component sample may be a number of optical absorbance values in a particular time interval. A preferred rate, for example, may be 100 optical absorbance values (or samples) per second, expressed 100/second. The sample rate preferably is used to derive a multiplier component, MUL. Also used to derive the multiplier component is the parity value, which is a multiplier utilized to create x-y pixel parity for the clotting curve information (that is shown expressed on the clotting curve graph, see FIG. 6). According to the example illustrated, the sampling rate used was 100 values per second. The pixel parity multiplier was 0.535. The multiplier, according to this example, is 0.535 (pixel parity value)/100 (the number of samples reflected in a second). The multiplier, or MUL, according to a preferred embodiment, was 0.00535.

In order to derive the INRn, the clotting curve is considered, and the theoretical or hypothetical zero order kinetic line, or line L as it is referred to and appears on the Figures, provides an (x,y) coordinate of (TEOT, 0), where the time value at which the clotting reaction, if theorized from the slope or line taken between the point where the maximum acceleration of the conversion rate of fibrinogen transformation begins (T2S) and the end of the maximum conversion (which is the last highest delta value of conversion rate), which is T2 or Tmap. The value, TEOT, is a time value, and generally, for example, may be expressed in seconds. As illustrated, the right side S2, may be designated to correspond with the line formed between the point (t1, c1) and TEOT. According to an alternate embodiment, the slope of the line L may corresponds with the slope of the side S2 of trapezoidal Area T. For example, according to some embodiments, the line L may form the side S2 of the trapezoid whose area is illustrated as Area T.

As shown in the preferred embodiments illustrated in FIGS. 6 and 7, a segment of the line from TEOT and the point on the clotting curve T1, forms the trapezoid side S2.

With the multiplier MUL, the INRn may be derived according to the following expression:

INRn=((T1+TEOT)/2)*0.00535*T2  (11)

As illustrated in FIG. 7, the lower base, S4, of the trapezoid TP, is the time value of the theoretical or hypothetical end of the coagulation test, TEOT. The time value component TEOT includes the time value of T2 plus the time value (Tiut) to convert the remainder of the fibrinogen in the sample that is considered to provide active optical activity (by the theoretical time value of the end of the test, TEOT). Both the Teot and TSot are values that are determined from the absorbance readings for a sample in a coagulation reaction. Dividing the difference in Instrument Units (RU)@ T2S to IU@ T2 (which is IUX) by the time it takes this conversion T2S to T2 (which may be represented by the time interval, Tiux) gives the maximum transformation rate for a specific sample. Using this specific test rate (UX/Tiux), it is determined how long it would take to convert the fibrinogen from T2S to T3 (end of test) and add this value to T2S. This gives the TEot. Another value listed in the data Table 14 is the TSot which is the hypothetical start of test. The TSot is similar to the TEot, the hypothetical end of test. (The TEot, according to some embodiments, also may be referred to herein as a theoretical end of test.) The time that it takes to convert the IU@T1 to IU@T2S (which may be expressed as the difference between T1 and T2S (the value Tcon)) may be determined using the same rate of change. The TSot is determined by subtracting the time (Tcon) from T2S to give the TSot. The TSot may come before or after T1 and the TEot will always come before T3.

Referring again to FIG. 7, an upper base, S3, is indicated to correspond with the time of the start of the clot formation when the coagulation reaction is carried out. The start time of the clotting is represented by the time, T1, as shown in FIG. 6. With the upper and lower bases, S3 and S4, respectively, being ascertained through the clotting reaction times, they may be averaged (e.g., divided by 2). The S3, S4 average may be used to derive a trapezoidal area, such as, for example, Area T, represented by the clotting absorbance signal data. The altitude S1 (or height) of the trapezoidal area, Area T, is derived by the value of the point of time (T1) where the beginning of the conversion of fibrinogen to fibrin for the patient sample is determined. That point is represented as time value T1 on FIGS. 6 and 7. The height component of the trapezoid represented by Area T is designated to correspond with the side S1. The height component is assigned the value T1*MUL (T1 multiplied by the multiplier).

The INRn may be determined for a patient sample by determining (i) when the clot formation begins, which is represented by the time value T1, (ii) when the clotting commences a maximum conversion rate (of conversion of fibrinogen to fibrin in the patient sample), which is represented by the time value T2, and (iii) the end of the maximum conversion rate, represented by the time value T3 (the end of the maximum conversion rate). Therefore, according to embodiments of the present method and apparatus, a new INR determination that, through the transformation of information (e.g., signals corresponding to optical activity of a clotting reaction), may be derived by (i) determining the start of the clotting when a reagent (such as, for example, thromboplastin C) is reacted with a blood or blood component sample of a person (by determining the length of time from the introduction of the reagent and sample to the time clotting begins, which is T1), (ii) determining the start of the maximum acceleration rate of conversion for the clotting reaction that began at time T1) which is represented by the time T2, and (ii) determining the value of the end of the maximum conversion rate for the clotting reaction, which is represented by the value T3.

The present method and apparatus may be used to derive an INR, IRn, which does not utilize exponential components, and therefore, is not subject to exponential inaccuracies that have previously been experienced in connection with traditional INR determinations. The INRn value may be used to monitor a patient's blood or blood components for administration of oral anticoagulant therapy, such as, for example, coumarin, and other treatment agents, including those discussed herein. The present method and apparatus preferably, according to a preferred embodiment, where INRn is derived (and may be used for treatment administration of anticoagulant therapy).

The clotting curve illustrates a representation of absorbance values for a clotting reaction where substantially optically clear fibrinogen converts to turbid fibrin, hence reducing the absorbance unit values, as indicated on the abscissa. The point of intersection of the line L with the x-axis, or the time axis, preferably, may be derived using the value T2S and adding to that time value, the time required to convert additional fibrinogen in the sample, which is the time value corresponding with the absorbance value IUT (in instrument units). The TEOT value may be derived from the intercept that the slope of the line L defined by T2S and T2 makes with the x-axis. However, as described herein, the x axis would, in theory, be where y=0, and accordingly, since some signal may be detected (and hence not zero), the trapezoidal lower base S4 (FIGS. 6 and 7) may be represented along y=Ceot, between times T0 and TEot. According to a preferred embodiment, the TEOT value may be derived by the following determination:

TEOT=T2S+(ZTM/IUX*IUT)  (12)

where ZTM is the time (in seconds) to convert the fibrinogen corresponding to the time interval between T2S and T2, or in other words, the time to convert the IUX absorbance value (the IUX being the difference between instrument units (or IU) at T2S (IU@T2S) and instrument units at T2 (IU@T2)). The IUT value is the difference between instrument units (or IU) at T2S (IU@T2S) and instrument units at T3 (IU@T3).

A method was carried out using the Dade Behring Thromboplastin C Plus (Dade TPC+) as the reagent. The number of patient samples that were reacted and used to obtain the following data was 218. The WHO INR (the World Health Organization INR is the average of INR values from five different thromboplastins. The INRm is the manufacturer's INR. INRz is the INR that is derived using the exponent (2-FTR) instead of the ISI (as described herein (see formulae (1), (2), (3), (3.1), above). INRn (uses no ISI and no MNPT values for its determination) and is the calculation for the INR in accordance with the alternate embodiment described herein and represented by the formula INRn=((T1+TEOT)/2)*0.00535*T2, which is formula (II), above.

Coagulation reactions were carried out for a number of individuals, using the blood samples from the individuals, prepared as indicated herein in connection with clotting reactions, where a clotting reagent is added to the blood sample, and preferably a blood plasma sample. The absorbance values (measured in instrument units) were obtained for the sample throughout the coagulation reaction using a linear-output photo-optical coagulometer, POTENS+. The clotting agent used was thromboplastin reagent (Tp) which was injected into citrated human blood plasma. The clotting curve absorbance values were tracked as optically-clear fibrinogen (Fg) (also referred to as FBG herein) converts into turbid fibrin. The table below provides the values of the absorbance and time data that was obtained. By extending the slope L derived by the slope of the curve where the maximum conversion rate of fibrinogen occurs, a trapezoid is formed whose area may be derived and used to provide a value, INRn, which is essentially equal to the traditionally obtained INR values.

TABLE 12 Comparative Summary INR WHO (INRw) NG LASSEN Agreement Poller Highest Versus Discordant <=0.4 <=0.7 Diff >10% Percent vs. INR_(M) 13.8% 85.3% 95.9%  9/218 4.1% 18.3% vs. INR_(Z) 10.1% 89.4% 96.3%  7/218 3.2% 15.2% vs. INR_(N) 9.2% 88.5% 96.3% 12/218 5.5% 14.8%

Table 12 provides comparative data for INRn, INRz and INRn values compared with INR values calculated by the INR WHO method (which is also represented as INRw). The INR obtained using the WHO method (INRw) was compared with each of the alternate INR determinations, including INRm (using the manufacturer's INR), INRz, using the expressions of the above formulae (1), (2), (3), (3.1), as discussed herein, and INRn, using the expressions of the above formulae (10), (11), (12).

Further details of the comparative data are provided in Table 13 to illustrate values for each of the INR WHO comparisons.

TABLE 13 COMPARATIVE SUMMARY DETAILS using DADE TPC+ Thromboplastin WHO INR vs INRm Specimens Using NG algorithm Number of mismatches 30/218 = 13.8% Range <2.0 13(13, 0)/79 16.5% Range  2.0 to 3.0 12(10, 2)/91 13.2% Range >3.0 to 4.5  5(4, 1)/37 13.5% Range >4.5  0(0, 0)/11 0.0% Lassen values Samples: 218 delta <= 0.4 32@85.3% delta <= 0.7 9@95.9% WHO INR vs INRz Specimens Using NG algorithm Number of mismatches 22/218 = 10.1% Range <2.0 11(11, 0)/79 13.9% Range  2.0 to 3.0  5(4, 1)/91 5.5% Range >3.0 to 4.5  5(2, 3)/37 13.5% Range >4.5  1(0, 1)/11 9.1% LASSEN values Samples: 218 delta <= 0.4 23@89.4% delta <= 0.7 8@96.3% INRw vs. INRn Specimens Using NG algorithm Number of mismatches 20/218 = 9.2% Range <2.0  1(1, 0)/79 1.3% Range  2.0 to 3.0 13(4, 9)/91 14.3% Range >3.0 to 4.5  6(4, 2)/37 16.2% Range >4.5  0(0, 0)/11 0.0% LASSEN values Samples: 218 delta <= 0.4 25@88.5% delta <= 0.7 8@96.3% The sample data upon which the above data summaries were based, is provided in Table 14. Table 14 provides corresponding data for a coagulation study. In Tables 14 and 15, the following references are used, and may be further identified by reference to FIG. 8:

-   -   ID—Sample ID     -   T0—Time of thromboplastin reagent injection     -   T1—Start of the clot formation     -   T2S—Start of maximum conversion rate     -   T2—End of maximum conversion rate. (Last highest delta value of         conversion rate.)     -   T3—(T₄−T_(2s))     -   T4—Hypothetical End Of Test (HEOT)     -   IU—Instrument unit     -   IUT—Delta IU between IU@T2S and IU@T3     -   IUX—Delta IU between IU@T2S and IU@T2     -   IUA—Altitude component value of the trapezoidal area (in         instrument units) (c1—ceot)     -   IUL—Length component value of the trapezoidal area (in         instrument units)     -   ZTM—Time in seconds to convert the IUX (T2−T2S)     -   TEOT—Hypothetical End Of Test. (Time at T2S plus the time to         convert IUT.)     -   TSot—Hypothetical Start Of Test     -   Fg—Fibrinogen concentration of the blood sample (in g/l)     -   c1—Absorbance value (in instrument units) at time of the start         of the clot formation (T1)     -   cT2S —Absorbance value (in instrument units) at the time of the         start of maximum conversion rate (T2S)     -   c2—Absorbance value (in instrument units) at time of the end of         maximum conversion rate     -   (T2). (Last highest delta value of conversion rate.)     -   ceot—Absorbance value (in instrument units) at time TEOT

TABLE 14 ID WHO INRm INRz INRn T1 T2S T2 T3 TSot TEot A001 3.00 3.08 2.55 2.38 18.89 22.04 23.89 49.55 19.66 29.44 A002 2.88 3.32 2.56 2.19 19.71 23.00 24.42 37.75 20.87 27.61 A003 2.78 3.33 2.55 2.41 19.75 23.10 25.48 37.55 20.94 28.51 A004 2.08 2.03 2.03 1.66 14.85 19.66 21.62 37.55 16.89 24.96 A005 2.30 2.87 2.31 2.04 18.11 21.69 23.83 37.55 19.36 26.75 A007 1.85 2.03 1.78 1.45 14.86 18.19 20.18 33.95 15.87 22.83 A008 2.83 2.62 2.42 2.17 17.22 21.59 23.63 41.95 18.97 28.20 A009 2.70 3.38 2.65 2.47 19.91 23.91 26.43 37.87 21.39 29.31 A010 1.65 1.88 1.61 1.24 14.22 17.16 19.27 30.15 14.73 21.38 A011 1.83 2.09 1.71 1.34 15.10 17.90 19.32 33.75 15.57 22.26 A012 2.68 3.17 2.47 2.03 19.21 22.40 23.94 36.95 19.78 27.33 A013 3.30 3.44 2.92 2.86 20.13 24.09 26.68 50.15 21.60 31.76 A014 1.60 1.78 1.55 1.12 13.76 17.01 18.35 30.15 14.78 20.43 A015 1.70 1.88 1.60 1.20 14.23 17.15 18.96 28.30 14.74 21.17 A016 2.73 3.02 2.53 2.14 18.68 22.33 23.35 45.75 19.91 27.94 A017 1.70 1.78 1.63 1.24 13.76 17.29 18.86 31.35 14.82 21.66 A018 2.18 2.17 1.91 1.60 15.44 18.77 21.23 34.55 16.09 24.36 A019 1.85 1.82 1.71 1.41 13.97 17.58 19.30 36.75 15.29 22.74 A020 3.80 3.52 2.93 2.75 20.40 25.35 28.02 42.75 22.47 31.31 A021 2.63 2.83 2.39 2.08 17.98 21.51 23.37 37.35 18.91 27.65 A022 2.08 2.18 1.92 1.59 15.46 19.01 20.55 36.75 16.65 24.14 A023 3.20 3.11 2.55 2.20 18.98 22.51 23.92 43.35 20.09 28.15 A024 3.03 3.39 3.05 2.81 19.94 25.22 27.22 45.28 22.66 31.44 A025 1.73 1.84 1.51 1.06 14.03 16.98 18.01 27.40 15.09 19.73 A026 1.45 1.60 1.45 1.11 12.94 15.96 17.58 31.69 13.53 20.52 A027 1.45 1.48 1.36 1.05 12.41 15.34 16.91 33.35 13.12 19.77 A028 1.90 1.93 1.73 1.41 14.41 17.80 19.22 39.15 15.38 22.98 A029 2.20 2.06 1.85 1.59 14.99 18.36 20.31 40.55 16.07 23.96 A030 2.50 2.61 2.25 2.05 17.17 20.52 22.08 48.75 18.18 27.54 A031 2.43 2.75 2.25 1.95 17.69 21.07 23.20 35.84 18.55 26.49 A032 3.63 3.83 3.33 2.88 21.40 25.84 26.78 48.15 23.33 32.26 A033 2.65 2.94 2.52 2.22 18.39 22.44 24.46 41.95 19.79 28.37 A034 2.08 2.24 1.96 1.69 15.71 19.14 20.89 38.95 16.92 24.62 A035 4.00 4.87 3.71 4.36 24.58 29.96 34.33 47.75 27.15 38.08 A036 2.98 3.19 2.51 2.47 19.26 21.94 24.50 43.55 19.89 29.11 A037 2.20 2.50 2.32 1.97 16.73 21.61 23.71 36.95 18.96 26.80 A038 1.45 1.57 1.35 0.99 12.82 15.48 16.81 29.69 13.15 19.36 A039 1.50 1.46 1.39 0.99 12.27 15.70 17.37 28.67 13.27 19.34 A040 2.28 2.39 2.06 1.79 16.33 19.59 21.24 39.75 17.17 25.75 A041 2.18 2.30 2.14 1.88 15.95 19.93 21.44 45.15 17.29 26.82 A042 3.40 4.07 3.36 3.15 22.16 26.65 29.21 49.35 23.45 33.90 A044 3.38 4.31 3.31 2.90 22.90 26.85 28.41 41.15 24.38 31.92 A045 2.60 2.70 2.44 2.26 17.52 21.56 24.20 45.75 18.92 28.64 A047 2.45 2.81 2.46 2.24 17.90 21.99 24.21 41.55 19.51 28.26 A048 3.38 3.82 3.13 3.15 21.35 25.34 28.49 46.15 22.61 33.32 A049 2.28 2.68 2.15 1.99 17.42 20.04 22.56 39.55 17.88 26.34 A050 2.70 2.80 2.49 2.17 17.86 22.06 24.08 40.75 19.20 28.46 A051 1.88 1.91 1.64 1.32 14.35 17.45 18.41 35.55 15.19 22.32 A052 2.55 2.82 2.31 2.05 17.94 20.98 22.93 40.35 18.50 27.36 A053 2.88 3.06 2.48 2.09 18.82 22.39 24.07 38.75 19.78 27.62 A054 1.90 2.07 1.78 1.48 15.04 18.09 20.21 33.15 15.84 22.99 A055 6.58 5.56 4.81 5.66 26.51 31.27 36.08 70.15 28.32 45.39 A056 3.48 3.58 3.19 3.09 20.60 25.34 27.68 53.15 22.73 33.17 A057 2.58 2.85 2.23 1.87 18.05 21.05 22.66 35.15 18.72 25.88 A058 7.40 8.47 7.73 8.65 33.76 41.78 45.33 79.97 37.98 55.47 A059 2.25 2.93 2.27 1.99 18.34 21.38 23.74 34.15 18.82 26.69 A060 2.43 3.15 2.54 2.21 19.12 23.19 25.32 36.55 20.59 28.16 A061 2.25 2.49 2.17 1.97 16.70 20.05 22.25 38.35 17.68 26.82 A062 6.35 6.20 6.43 6.80 28.21 37.32 40.28 78.95 33.62 49.72 A063 2.65 3.04 2.63 2.61 18.75 22.31 25.84 42.15 19.59 30.73 A064 2.05 2.21 1.92 1.55 15.59 19.19 21.08 32.55 16.76 23.78 A065 2.28 2.65 2.47 2.22 17.32 22.25 24.96 39.75 19.39 28.42 A066 1.83 1.99 1.67 1.24 14.69 17.83 19.19 30.15 15.50 21.52 A067 1.78 1.75 1.62 1.30 13.63 17.02 18.52 36.75 14.49 22.31 A068 2.68 2.65 2.13 1.90 17.30 19.97 21.86 37.35 17.76 26.11 A069 2.10 2.41 1.92 1.41 16.41 19.35 20.15 31.95 16.95 23.19 A070 1.65 2.38 1.97 1.58 16.29 19.40 20.80 37.55 16.92 24.25 A071 1.73 1.89 1.73 1.44 14.25 17.63 19.53 39.50 15.23 23.03 A072 1.60 1.82 1.69 1.45 13.97 17.27 18.98 43.55 14.80 23.54 A073 1.48 1.49 1.50 1.21 12.46 16.14 17.82 37.75 13.77 21.33 A074 1.65 1.71 1.59 1.26 13.44 16.86 19.03 33.35 14.56 21.33 A075 1.58 1.57 1.21 0.75 12.80 14.89 15.87 23.28 13.18 16.85 A076 1.45 1.44 1.37 1.11 12.18 15.39 16.78 37.55 13.01 20.65 A077 4.63 4.64 4.03 4.26 23.88 28.45 31.55 64.71 25.61 39.30 A078 2.05 2.16 1.88 1.64 15.41 18.55 20.89 35.71 16.35 24.06 A080 6.13 7.35 6.42 8.00 31.12 35.48 40.50 86.95 32.86 55.56 A081 3.55 3.76 3.63 3.30 21.18 26.98 28.55 57.95 23.84 35.22 A082 1.53 1.54 1.55 1.29 12.69 16.24 18.15 43.55 13.76 22.16 A083 1.60 1.60 1.38 0.98 12.97 15.82 16.98 28.23 13.50 19.41 A084 6.98 6.67 5.72 6.91 29.43 33.64 38.19 76.55 30.96 51.04 A085 3.10 3.27 3.01 3.29 19.55 24.14 29.21 48.15 21.22 34.28 A086 2.45 2.85 2.35 2.11 18.07 21.11 22.84 46.95 18.57 27.93 A087 1.93 1.84 1.69 1.40 14.06 17.40 19.24 37.00 15.03 22.74 A088 1.78 1.71 1.64 1.35 13.44 17.15 18.79 37.95 14.80 22.43 A089 2.18 2.28 1.83 1.44 15.90 18.76 20.00 33.95 16.62 22.82 A090 5.93 6.31 5.59 6.68 28.51 33.63 38.36 84.35 30.64 49.81 A091 8.23 7.68 6.96 7.83 31.91 38.95 42.75 74.75 35.15 53.48 A092 2.00 1.91 2.03 1.81 14.36 19.10 21.48 50.15 16.41 26.06 A093 4.30 4.86 3.81 4.26 24.53 28.21 31.94 53.15 25.81 38.07 A094 2.53 3.17 2.94 2.41 19.18 24.61 25.77 42.95 22.06 29.60 A095 1.43 1.50 1.43 1.15 12.48 15.73 17.24 37.76 13.36 20.91 A096 1.80 2.12 1.69 1.29 15.22 17.85 19.14 30.95 15.59 21.88 A097 1.40 1.32 1.11 0.76 11.59 13.74 14.88 27.05 11.21 17.41 A098 1.45 1.40 1.32 1.04 11.98 14.78 16.59 34.95 12.54 19.69 A099 1.53 1.81 1.52 1.17 13.93 16.63 18.24 30.15 14.48 20.60 A100 1.40 1.41 1.40 1.18 12.06 15.39 17.01 39.15 13.23 21.06 A101 2.45 2.76 2.39 2.26 17.71 21.22 24.16 42.97 18.67 28.47 A102 3.83 3.79 3.13 2.90 21.28 24.77 25.93 56.17 22.32 32.50 A103 2.15 2.03 1.94 1.74 14.84 18.67 20.63 45.75 16.35 25.35 A104 3.10 3.21 2.96 3.01 19.32 23.44 27.32 50.53 20.39 33.69 A105 3.85 3.69 3.15 3.34 20.93 24.28 26.92 63.15 22.14 35.01 A107 2.53 2.84 2.42 2.36 18.01 21.27 23.85 50.16 19.06 28.89 A108 1.95 2.08 1.85 1.55 15.06 18.37 20.98 32.12 15.76 23.83 A109 2.28 2.27 2.06 1.85 15.86 19.19 22.04 38.31 16.53 26.22 A110 3.83 3.91 3.72 4.05 21.65 26.20 29.96 67.75 23.26 39.93 A111 2.90 2.52 2.39 2.35 16.84 20.64 24.09 45.11 18.13 29.42 A112 2.30 2.39 2.22 2.13 16.33 20.00 22.03 56.41 17.63 28.46 A113 1.80 1.87 1.65 1.41 14.17 16.98 18.78 38.35 14.73 22.94 A114 1.90 2.10 1.87 1.65 15.13 18.38 20.51 43.35 16.14 24.34 A115 2.10 2.38 2.30 2.03 16.26 20.91 22.84 47.35 18.27 27.41 A116 1.78 1.73 1.40 1.07 13.53 15.66 17.28 29.70 13.64 19.58 A117 1.65 1.62 1.65 1.45 13.04 16.91 18.76 49.15 14.58 23.34 A118 1.98 2.18 1.80 1.46 15.46 18.36 19.65 35.35 16.10 23.20 A119 2.65 2.98 2.43 2.32 18.53 21.29 23.20 48.14 19.06 29.09 A120 1.85 2.11 1.79 1.48 15.18 18.33 19.61 34.35 16.20 23.17 A121 2.05 2.21 1.82 1.58 15.60 18.24 20.28 36.04 16.20 23.54 A122 1.55 1.76 1.64 1.42 13.70 16.76 18.82 42.35 14.50 22.94 A123 1.70 1.81 1.55 1.25 13.91 16.51 18.38 31.51 14.27 21.37 A124 1.63 1.80 1.46 1.08 13.85 16.27 17.67 29.01 13.94 20.16 A125 1.50 1.39 1.26 1.04 11.93 14.86 15.88 37.95 12.41 20.50 A126 3.25 3.70 2.97 3.02 20.99 25.08 28.61 41.35 22.26 32.49 A127 2.20 2.38 2.05 1.83 16.28 19.39 20.92 51.15 16.81 26.47 A128 3.38 3.89 3.06 2.64 21.58 24.88 26.01 47.86 22.48 30.67 A129 4.35 5.25 4.67 4.77 25.65 30.83 33.84 60.80 27.13 42.64 A130 4.05 4.66 4.55 4.16 23.94 31.39 33.06 58.52 28.41 38.43 A131 1.63 1.72 1.68 1.42 13.49 17.05 19.42 34.86 14.68 22.81 A132 2.43 2.65 2.75 2.62 17.33 22.89 26.55 47.95 19.39 31.64 A133 2.65 2.64 2.56 2.63 17.27 21.32 25.37 48.11 18.85 31.00 A134 6.33 6.48 6.27 6.27 28.95 36.89 39.54 62.23 32.81 48.31 A135 1.40 1.49 1.32 0.97 12.42 15.07 16.62 30.63 12.59 19.31 A136 4.38 4.33 3.63 3.63 22.96 26.93 29.17 62.05 24.27 36.17 A137 1.58 1.96 1.73 1.33 14.56 18.09 19.56 35.32 15.80 22.09 A138 2.18 1.99 2.04 1.74 14.69 19.49 21.15 46.15 16.78 25.69 A139 2.05 2.12 1.97 1.78 15.24 19.05 20.42 48.75 16.77 25.90 A140 1.35 1.34 1.28 1.01 11.72 14.83 16.21 38.35 12.55 19.52 A141 2.05 2.22 1.87 1.52 15.65 18.77 20.00 34.32 16.40 23.78 A142 3.10 3.36 2.60 2.24 19.86 23.90 25.80 37.58 21.43 28.27 A143 2.08 2.56 2.23 2.08 16.97 20.55 23.80 37.75 17.91 27.25 A144 2.20 2.44 2.12 1.76 16.53 20.17 21.49 41.68 17.76 25.45 A145 1.28 1.38 1.28 0.99 11.91 14.81 16.17 36.48 12.38 19.53 A146 2.48 2.26 1.98 1.80 15.81 18.99 20.67 49.55 16.66 25.97 A147 1.48 1.64 1.45 1.10 13.14 16.08 17.38 34.14 13.57 20.59 A148 2.18 2.38 2.07 1.79 16.28 19.67 21.10 46.95 17.00 26.15 A149 1.33 1.52 1.41 1.05 12.57 15.82 17.19 34.20 13.23 20.16 A150 1.45 1.55 1.40 1.14 12.72 15.57 16.97 39.21 13.27 20.78 A151 2.83 2.80 2.52 2.42 17.89 21.77 24.31 56.93 19.30 29.60 A152 1.85 2.19 1.82 1.34 15.50 18.79 20.08 33.19 16.21 22.66 A153 1.73 1.77 1.64 1.41 13.75 17.14 18.49 46.91 14.70 23.25 A154 2.30 2.29 1.97 1.75 15.94 18.86 20.90 41.84 16.50 25.41 A155 4.98 4.80 3.87 4.77 24.37 29.06 35.08 53.55 26.05 40.50 A156 2.80 2.77 2.40 1.89 17.76 21.91 23.03 40.00 19.35 26.55 A157 2.03 2.22 1.87 1.52 15.64 18.86 20.65 36.62 16.47 23.51 A158 3.43 3.64 2.84 2.55 20.79 24.24 25.84 44.53 22.00 29.68 A159 3.78 3.94 3.60 3.72 21.74 26.43 29.76 61.35 23.28 37.47 A160 2.58 2.74 2.47 2.40 17.64 21.60 24.95 44.35 18.99 29.29 A161 1.68 1.66 1.60 1.31 13.24 16.74 18.54 35.95 14.17 22.40 A162 7.33 6.56 5.90 6.52 29.16 34.82 38.19 74.78 31.45 49.35 A163 3.90 3.90 3.15 3.04 21.62 25.10 27.09 49.55 22.75 32.70 A164 3.45 3.79 3.19 2.83 21.28 25.53 26.93 47.44 23.08 31.66 A165 2.63 2.60 2.25 1.96 17.13 20.69 22.34 43.75 18.17 26.86 A166 2.05 2.19 1.91 1.62 15.52 18.84 20.12 42.98 16.44 24.60 A167 2.65 3.00 2.45 1.91 18.61 22.28 23.38 36.00 19.77 26.68 A168 3.60 3.61 3.03 3.20 20.68 23.69 25.98 51.55 21.61 34.72 A169 3.78 4.13 3.34 3.14 22.35 25.61 26.64 60.89 23.24 33.75 A170 1.30 1.37 1.24 0.88 11.84 14.56 16.01 30.00 12.18 18.39 A171 3.18 3.41 2.94 3.02 20.01 24.48 27.83 47.95 21.97 32.30 A172 2.58 2.58 1.99 1.71 17.06 19.43 20.73 39.75 17.41 24.63 A173 1.48 1.51 1.30 0.95 12.55 15.03 16.46 28.97 12.78 18.91 A174 1.88 1.84 1.60 1.31 14.04 16.86 18.51 36.75 14.60 21.98 A175 1.60 1.84 1.52 1.13 14.02 16.78 18.20 29.70 14.61 20.37 A176 3.08 3.33 2.82 2.72 19.75 23.45 25.14 50.35 21.34 30.91 A177 1.58 1.73 1.42 1.05 13.56 15.96 17.33 31.35 13.59 19.95 A178 2.53 2.34 2.16 1.89 16.13 20.20 21.83 43.07 17.75 26.41 A179 2.33 2.51 2.18 1.86 16.78 20.38 22.02 39.95 17.86 26.18 A180 2.18 2.26 1.88 1.59 15.79 18.80 20.33 36.32 16.66 23.85 A181 3.68 3.49 3.21 3.44 20.29 25.17 29.85 51.67 21.98 35.38 A182 2.05 2.10 1.78 1.44 15.15 18.28 19.30 39.14 15.93 23.28 A183 1.53 1.55 1.30 0.91 12.70 15.24 16.46 28.49 12.95 18.59 A184 2.48 2.58 2.22 1.96 17.06 20.49 21.89 47.65 18.04 27.02 A185 3.05 3.28 2.96 2.87 19.59 24.06 26.64 54.15 21.37 32.25 A186 3.10 3.12 3.09 3.58 19.01 22.19 29.51 65.55 19.65 37.28 A187 1.75 1.83 1.51 1.18 13.99 16.52 17.86 34.85 14.22 21.02 A188 2.93 3.12 2.56 2.46 19.01 22.29 24.63 36.67 20.11 29.31 A189 2.93 2.98 2.68 2.47 18.52 23.20 25.87 44.13 20.26 30.01 A190 3.25 3.59 3.00 2.75 20.62 24.60 26.72 44.63 21.77 31.67 A191 2.05 2.04 1.71 1.39 14.91 17.82 19.08 34.18 15.77 22.39 A192 2.28 2.49 2.25 1.81 16.69 21.28 22.69 39.02 18.88 25.65 A193 1.95 2.11 1.84 1.64 15.20 17.86 20.52 39.35 15.51 24.43 A194 2.18 2.27 1.98 1.72 15.83 19.27 21.44 36.83 16.93 24.78 A195 1.45 1.37 1.46 1.17 11.86 15.76 17.48 34.90 13.23 21.30 A196 1.95 1.99 1.82 1.56 14.68 18.04 20.23 42.94 15.59 23.97 A197 1.63 1.78 1.62 1.28 13.76 17.46 18.33 41.41 15.35 21.69 A198 1.85 1.92 1.66 1.43 14.39 16.92 19.77 31.95 14.88 22.21 A199 1.40 1.49 1.32 0.94 12.42 15.08 16.68 28.38 12.57 19.08 A200 1.35 1.38 1.21 0.88 11.92 14.39 15.64 30.32 12.02 18.39 A201 2.40 2.56 2.19 1.96 16.97 20.37 22.05 42.55 18.13 26.53 A202 2.20 2.39 1.93 1.59 16.31 18.99 20.82 37.23 16.43 24.30 A203 1.80 2.07 1.67 1.28 15.04 17.69 18.76 36.37 15.26 22.07 A204 1.73 1.80 1.50 1.14 13.85 16.41 17.97 30.75 14.07 20.62 A205 1.85 1.87 1.84 1.46 14.19 18.51 20.05 39.13 15.79 23.60 A207 2.65 2.75 2.42 2.11 17.69 21.70 23.07 45.74 19.37 27.59 A208 3.05 3.04 2.63 2.62 18.75 22.27 25.50 45.50 19.80 30.63 A209 1.70 1.84 1.69 1.44 14.06 17.22 19.31 37.35 15.00 22.84 A210 2.35 2.37 1.95 1.58 16.23 19.23 20.54 39.33 16.76 24.32 A211 2.50 2.68 2.40 2.12 17.44 21.54 23.03 47.55 19.14 27.75 A212 2.88 2.77 2.44 2.18 17.78 21.82 23.45 43.47 19.54 27.85 A213 2.53 2.74 2.40 2.41 17.65 20.57 23.19 56.75 18.23 30.50 A214 2.60 2.80 2.44 2.38 17.86 21.07 24.24 44.75 18.53 29.52 A215 2.40 2.47 2.06 1.70 16.63 19.82 21.16 41.43 17.36 25.07 A216 4.48 4.13 3.86 3.78 22.33 27.99 30.59 58.40 24.70 37.52 A217 2.23 2.33 2.26 2.19 16.10 20.21 22.30 63.13 17.82 28.77 A218 2.95 2.94 2.82 2.70 18.38 23.22 25.69 59.95 20.39 31.65 A219 2.38 2.71 2.17 2.01 17.55 20.69 23.43 36.97 18.50 26.17 A220 1.90 2.05 1.74 1.34 14.92 18.06 19.41 34.75 15.57 22.53 A222 1.83 1.89 1.63 1.36 14.27 17.07 18.81 33.95 14.98 22.12 A223 1.73 1.74 1.41 1.05 13.60 16.00 17.00 31.79 13.57 20.14 A224 1.73 1.62 1.52 1.15 13.03 16.52 18.07 31.77 14.04 20.86 A225 1.68 1.81 1.52 1.18 13.93 16.59 17.97 32.58 14.29 20.96

TABLE 15 Table 15 provides additional data for the coagulation study of the samples in Table 14. ID Fg c1 ct2s C2 Ceot IUL IUX IUT IUA Ztm A001 388 3738 3720 3706 3664 18 14 56 74 1.85 A002 226 3724 3712 3704 3686 12 8 26 38 1.42 A003 213 3740 3730 3719 3705 10 11 25 35 2.38 A004 370 3733 3709 3692 3663 24 17 46 70 1.96 A005 226 3738 3726 3715 3700 12 11 26 38 2.14 A007 244 3740 3726 3714 3698 14 12 28 42 1.99 A008 482 3741 3714 3693 3646 27 21 68 95 2.04 A009 253 3741 3727 3713 3697 14 14 30 44 2.52 A010 240 3742 3727 3714 3701 15 13 26 41 2.11 A011 352 3713 3690 3676 3647 23 14 43 66 1.42 A012 276 3744 3727 3717 3695 17 10 32 49 1.54 A013 496 3739 3715 3690 3641 24 25 74 98 2.59 A014 226 3732 3717 3708 3694 15 9 23 38 1.34 A015 199 3738 3726 3717 3706 12 9 20 32 1.81 A016 340 3741 3722 3714 3678 19 8 44 63 1.02 A017 331 3742 3720 3706 3681 22 14 39 61 1.57 A018 218 3734 3722 3711 3697 12 11 25 37 2.46 A019 472 3744 3716 3695 3653 28 21 63 91 1.72 A020 246 3741 3727 3714 3698 14 13 29 43 2.67 A021 265 3741 3727 3717 3694 14 10 33 47 1.86 A022 387 3740 3717 3702 3667 23 15 50 73 1.54 A023 420 3743 3719 3705 3663 24 14 56 80 1.41 A024 415 3740 3717 3699 3661 23 18 56 79 2.00 A025 171 3743 3732 3726 3716 11 6 16 27 1.03 A026 363 3742 3718 3702 3673 24 16 45 69 1.62 A027 377 3739 3715 3698 3667 24 17 48 72 1.57 A028 463 3742 3713 3696 3651 29 17 62 91 1.42 A029 472 3740 3713 3690 3647 27 23 66 93 1.95 A030 540 3743 3716 3698 3635 27 18 81 108 1.56 A031 236 3728 3715 3704 3687 13 11 28 41 2.13 A032 309 3732 3716 3710 3675 16 6 41 57 0.94 A033 358 3739 3718 3702 3671 21 16 47 68 2.02 A034 349 3740 3721 3706 3674 19 15 47 66 1.75 A035 209 3734 3725 3711 3699 9 14 26 35 4.37 A036 295 3735 3723 3708 3681 12 15 42 54 2.56 A037 372 3740 3716 3697 3669 24 19 47 71 2.10 A038 304 3742 3721 3709 3686 21 12 35 56 1.33 A039 232 3738 3722 3711 3698 16 11 24 40 1.67 A040 404 3742 3720 3705 3664 22 15 56 78 1.65 A041 493 3739 3711 3695 3638 28 16 73 101 1.51 A042 261 3736 3721 3709 3687 15 12 34 49 2.56 A044 301 3741 3722 3710 3683 19 12 39 58 1.56 A045 453 3739 3714 3689 3647 25 25 67 92 2.64 A047 341 3735 3716 3699 3668 19 17 48 67 2.22 A048 270 3733 3720 3705 3682 13 15 38 51 3.15 A049 252 3737 3725 3711 3690 12 14 35 47 2.52 A050 288 3740 3723 3711 3685 17 12 38 55 2.02 A051 514 3738 3705 3691 3634 33 14 71 104 0.96 A052 276 3737 3723 3712 3687 14 11 36 50 1.95 A053 241 3738 3724 3715 3696 14 9 28 42 1.68 A054 294 3733 3716 3700 3679 17 16 37 54 2.12 A055 540 3737 3718 3687 3627 19 31 91 110 4.81 A056 566 3740 3711 3685 3624 29 26 87 116 2.34 A057 232 3723 3710 3701 3683 13 9 27 40 1.61 A058 360 3738 3723 3709 3669 15 14 54 69 3.55 A059 232 3736 3723 3711 3696 13 12 27 40 2.36 A060 197 3730 3719 3710 3698 11 9 21 32 2.13 A061 294 3734 3720 3707 3680 14 13 40 54 2.20 A062 439 3738 3718 3702 3651 20 16 67 87 2.96 A063 237 3738 3728 3715 3697 10 13 31 41 3.53 A064 285 3737 3719 3705 3685 18 14 34 52 1.89 A065 320 3740 3721 3703 3680 19 18 41 60 2.71 A066 186 3738 3726 3719 3707 12 7 19 31 1.36 A067 494 3740 3708 3689 3641 32 19 67 99 1.50 A068 286 3739 3725 3713 3686 14 12 39 53 1.89 A069 223 3734 3719 3714 3695 15 5 24 39 0.80 A070 354 3739 3716 3703 3671 23 13 45 68 1.40 A071 399 3738 3714 3695 3660 24 19 54 78 1.90 A072 463 3738 3712 3694 3646 26 18 66 92 1.71 A073 494 3738 3707 3685 3639 31 22 68 99 1.68 A074 286 3718 3700 3683 3665 18 17 35 53 2.17 A075 114 3741 3734 3730 3726 7 4 8 15 0.98 A076 385 3742 3718 3704 3665 24 14 53 77 1.39 A077 508 3740 3718 3694 3634 22 24 84 106 3.10 A078 296 3740 3724 3707 3684 16 17 40 56 2.34 A080 499 3741 3729 3706 3637 12 23 92 104 5.02 A081 550 3742 3710 3694 3626 32 16 84 116 1.57 A082 431 3742 3716 3696 3654 26 20 62 88 1.91 A083 296 3742 3720 3709 3686 22 11 34 56 1.16 A084 376 3742 3732 3715 3667 10 17 65 75 4.55 A085 342 3742 3727 3701 3675 15 26 52 67 5.07 A086 448 3742 3717 3700 3650 25 17 67 92 1.73 A087 431 3742 3715 3694 3654 27 21 61 88 1.84 A088 512 3737 3704 3681 3630 33 23 74 107 1.64 A089 292 3742 3723 3712 3687 19 11 36 55 1.24 A090 711 3742 3718 3680 3588 24 38 130 154 4.73 A091 393 3741 3724 3707 3659 17 17 65 82 3.80 A092 711 3740 3696 3657 3582 44 39 114 158 2.38 A093 243 3739 3730 3716 3693 9 14 37 46 3.73 A094 322 3741 3719 3709 3676 22 10 43 65 1.16 A095 490 3743 3710 3689 3638 33 21 72 105 1.51 A096 214 3739 3725 3717 3700 14 8 25 39 1.29 A097 256 3741 3721 3712 3692 20 9 29 49 1.14 A098 398 3742 3716 3695 3659 26 21 57 83 1.81 A099 289 3742 3722 3707 3685 20 15 37 57 1.61 A100 536 3741 3709 3685 3625 32 24 84 116 1.62 A101 269 3740 3727 3712 3690 13 15 37 50 2.94 A102 397 3740 3721 3712 3661 19 9 60 79 1.16 A103 495 3741 3715 3693 3640 26 22 75 101 1.96 A104 260 3730 3719 3705 3682 11 14 37 48 3.88 A105 393 3738 3725 3709 3660 13 16 65 78 2.64 A107 402 3740 3722 3701 3660 18 21 62 80 2.58 A108 198 3743 3732 3721 3709 11 11 23 34 2.61 A109 273 3740 3726 3711 3689 14 15 37 51 2.85 A110 499 3737 3719 3696 3635 18 23 84 102 3.76 A111 366 3739 3723 3701 3667 16 22 56 72 3.45 A112 614 3742 3714 3690 3614 28 24 100 128 2.03 A113 371 3737 3717 3701 3664 20 16 53 73 1.80 A114 388 3732 3711 3691 3655 21 20 56 77 2.13 A115 446 3742 3716 3697 3652 26 19 64 90 1.93 A116 230 3742 3727 3715 3698 15 12 29 44 1.62 A117 499 3739 3710 3687 3630 29 23 80 109 1.85 A118 230 3743 3729 3721 3699 14 8 30 44 1.29 A119 308 3742 3728 3716 3679 14 12 49 63 1.91 A120 250 3737 3722 3713 3688 15 9 34 49 1.28 A121 196 3740 3730 3720 3704 10 10 26 36 2.04 A122 404 3736 3713 3692 3650 23 21 63 86 2.06 A123 205 3742 3730 3720 3704 12 10 26 38 1.87 A124 213 3736 3721 3712 3696 15 9 25 40 1.40 A125 541 3719 3683 3668 3600 36 15 83 119 1.02 A126 177 3743 3735 3725 3714 8 10 21 29 3.53 A127 482 3741 3714 3698 3640 27 16 74 101 1.53 A128 300 3740 3723 3715 3682 17 8 41 58 1.13 A129 338 3744 3728 3715 3677 16 13 51 67 3.01 A130 410 3740 3715 3701 3656 25 14 59 84 1.67 A131 258 3738 3724 3710 3690 14 14 34 48 2.37 A132 381 3742 3720 3697 3665 22 23 55 77 3.66 A133 347 3742 3728 3705 3673 14 23 55 69 4.05 A134 376 3743 3723 3710 3667 20 13 56 76 2.65 A135 330 3741 3717 3702 3676 24 15 41 65 1.55 A136 414 3744 3725 3709 3659 19 16 66 85 2.24 A137 381 3739 3711 3693 3662 28 18 49 77 1.47 A138 487 3743 3712 3693 3641 31 19 71 102 1.66 A139 478 3742 3717 3702 3642 25 15 75 100 1.37 A140 482 3743 3710 3690 3642 33 20 68 101 1.38 A141 373 3739 3714 3701 3661 25 13 53 78 1.23 A142 197 3742 3729 3719 3706 13 10 23 36 1.90 A143 239 3739 3726 3710 3693 13 16 33 46 3.25 A144 460 3740 3709 3692 3641 31 17 68 99 1.32 A145 465 3739 3705 3686 3639 34 19 66 100 1.36 A146 347 3736 3718 3705 3664 18 13 54 72 1.68 A147 385 3742 3713 3698 3661 29 15 52 81 1.30 A148 448 3742 3714 3699 3646 28 15 68 96 1.43 A149 427 3744 3710 3692 3653 34 18 57 91 1.37 A150 607 3742 3701 3676 3608 41 25 93 134 1.40 A151 698 3737 3701 3664 3587 36 37 114 150 2.54 A152 293 3738 3716 3705 3683 22 11 33 55 1.29 A153 626 3729 3691 3670 3596 38 21 95 133 1.35 A154 412 3728 3706 3687 3645 22 19 61 83 2.04 A155 365 3739 3724 3694 3667 15 30 57 72 6.02 A156 250 3733 3717 3710 3688 16 7 29 45 1.12 A157 310 3737 3717 3702 3678 20 15 39 59 1.79 A158 263 3737 3723 3713 3689 14 10 34 48 1.60 A159 404 3733 3715 3696 3652 18 19 63 81 3.33 A160 412 3738 3717 3690 3655 21 27 62 83 3.35 A161 331 3740 3720 3706 3676 20 14 44 64 1.80 A162 421 3738 3722 3706 3653 16 16 69 85 3.37 A163 293 3738 3725 3714 3683 13 11 42 55 1.99 A164 267 3734 3720 3712 3685 14 8 35 49 1.40 A165 485 3736 3707 3688 3636 29 19 71 100 1.65 A166 486 3733 3703 3687 3631 30 16 72 102 1.28 A167 235 3734 3718 3711 3690 16 7 28 44 1.10 A168 317 3732 3722 3711 3669 10 11 53 63 2.29 A169 486 3726 3703 3693 3624 23 10 79 102 1.03 A170 304 3740 3717 3703 3680 23 14 37 60 1.45 A171 365 3740 3722 3698 3666 18 24 56 74 3.35 A172 261 3741 3727 3718 3691 14 9 36 50 1.30 A173 304 3740 3718 3704 3680 22 14 38 60 1.43 A174 412 3733 3707 3688 3648 26 19 59 85 1.65 A175 378 3719 3690 3671 3642 29 19 48 77 1.42 A176 337 3739 3724 3712 3671 15 12 53 68 1.69 A177 267 3740 3721 3710 3689 19 11 32 51 1.37 A178 408 3740 3716 3700 3655 24 16 61 85 1.63 A179 329 3738 3718 3705 3672 20 13 46 66 1.64 A180 250 3733 3719 3709 3686 14 10 33 47 1.53 A181 317 3739 3724 3702 3676 15 22 48 63 4.68 A182 354 3739 3716 3706 3667 23 10 49 72 1.02 A183 209 3726 3711 3703 3689 15 8 22 37 1.22 A184 375 3738 3717 3705 3661 21 12 56 77 1.40 A185 458 3736 3712 3689 3639 24 23 73 97 2.58 A186 545 3738 3721 3672 3620 17 49 101 118 7.32 A187 350 3739 3715 3701 3668 24 14 47 71 1.34 A188 300 3731 3717 3702 3672 14 15 45 59 2.34 A189 358 3731 3709 3689 3658 22 20 51 73 2.67 A190 230 3730 3718 3709 3688 12 9 30 42 2.12 A191 234 3738 3725 3717 3696 13 8 29 42 1.26 A192 261 3739 3722 3712 3691 17 10 31 48 1.41 A193 301 3742 3727 3710 3685 15 17 42 57 2.66 A194 257 3735 3721 3708 3688 14 13 33 47 2.17 A195 716 3739 3692 3660 3589 47 32 103 150 1.72 A196 337 3738 3719 3702 3673 19 17 46 65 2.19 A197 502 3739 3705 3691 3637 34 14 68 102 0.87 A198 208 3728 3718 3704 3692 10 14 26 36 2.85 A199 301 3741 3719 3705 3684 22 14 35 57 1.60 A200 274 3737 3718 3708 3686 19 10 32 51 1.25 A201 319 3741 3725 3713 3681 16 12 44 60 1.68 A202 243 3737 3723 3713 3694 14 10 29 43 1.83 A203 364 3740 3715 3704 3670 25 11 45 70 1.07 A204 239 3739 3724 3714 3697 15 10 27 42 1.56 A205 346 3740 3717 3704 3674 23 13 43 66 1.54 A207 319 3728 3711 3701 3668 17 10 43 60 1.37 A208 306 3737 3724 3707 3680 13 17 44 57 3.23 A209 319 3742 3725 3709 3682 17 16 43 60 2.09 A210 283 3740 3723 3714 3688 17 9 35 52 1.31 A211 515 3741 3712 3694 3637 29 18 75 104 1.49 A212 279 3740 3726 3716 3689 14 10 37 51 1.63 A213 448 3741 3724 3705 3652 17 19 72 89 2.62 A214 283 3739 3727 3712 3687 12 15 40 52 3.17 A215 359 3737 3715 3703 3668 22 12 47 69 1.34 A216 389 3741 3722 3707 3667 19 15 55 74 2.60 A217 560 3740 3716 3695 3630 24 21 86 110 2.09 A218 773 3738 3699 3665 3583 39 34 116 155 2.47 A219 238 3741 3729 3714 3699 12 15 30 42 2.74 A220 356 3741 3717 3704 3674 24 13 43 67 1.35 A222 233 3725 3713 3703 3684 12 10 29 41 1.74 A223 257 3741 3724 3717 3695 17 7 29 46 1.00 A224 351 3742 3718 3703 3676 24 15 42 66 1.55 A225 314 3741 3721 3709 3683 20 12 38 58 1.38 Though the sample ID's in Tables 14 and 15 range from A0001 to A225, gaps in sample numbers indicate occurrences where a sample was not able to be tested because they were beyond three standard deviations.

TABLE 16 R² mY INRw vs TPC INRm 0.9482 1.0506x TPC INRz 0.9482 1.0389x TPC INRn 0.9401 1.048x INRw vs INRm −0.0908 −0.0186x INRz −0.0966 −0.0144x INRn 0.0327 −0.0065x The linear regression analysis expression y=m×+b, when solved for the slope, m, is expressed as (y−b)/x. This is biased, so the expression is y/x is when b is equal to zero. The comparison in Table 16, above, provides comparative data for mean y (mY) and mean x (mX) values, including the slope mY/mX. The use of the mY/mX is used to provide comparative results. The data in Table 16 is also represented on the Bland-Altman plots shown in FIGS. 8, 9, 10 and 11. The statistical data and plots demonstrate that the INRn may replace prior WHO INR and provide results which are within the parameters of traditional therapeutic or reference ranges.

In accordance with one embodiment, the IBM-compatible computer 30 of FIG. 1 stores and manipulates these digital values corresponding to the clotting curve represented in FIG. 6 and the related data provided in Tables 14 and 15. According to a preferred embodiment, the computer may be programmed as follows:

-   -   (k) a sample of blood where the plasma is available, such as,         for example, a sample of citrated blood, is obtained and placed         in an appropriate container, the computer 30, as well as the         recorder 28, sequentially records voltage values for a few         seconds before injection of the reagent (thromboplastin calcium         combined). As previously discussed, thromboplastin (tissue         factor) is one of the factors in the human body that causes         blood to clot. Prothrombin is another. Fibrinogen is yet         another. Before injection of the thromboplastin, the output from         the A/D converter 26 is relatively constant. When thromboplastin         is injected into the plasma sample in the container, a         significant and abrupt change occurs in the recorded voltage         values of both the computer 30 and the recorder 28. This abrupt         change is recognized by both the recorder 28 and, more         importantly, by the computer 30 which uses such recognition to         establish T_(o). The computer 30 may be programmed so as to         correlate the digital quantities of the A/D converter 26 to the         analog output of the detector means photocell 10 which, in turn,         is directly correlatable to the fibrinogen (FBG) concentration         g/l of the sample of blood discussed herein and represented by         the clotting curve shown in FIG. 6;     -   (l) the computer 30 may be programmed to look for a digital         quantity representative of a critical quantity F1, and when such         occurs, record its instant time T₁. (The time span between T_(o)         and T₁ is the prothromibin time (PT), and has an normal duration         of about 12 seconds, but may be greater than 30 seconds);     -   (m) following the detection of the quantity c₁, the computer 30         may be programmed to detect for the acceleration of fibrinogen         (FBG) to fibrin conversion. The computer 30 is programmed to         detect the maximum acceleration quantity c_(MAP) or c_(T2) as         illustrated in FIG. 6, and its corresponding time of occurrence         t_(MAP), which is T2 in FIG. 6.     -   (d) The computer detects a quantity c_(EOT) occurring at time         t_(EOT). Typically, it is important that the rate of fibrin         formation increase for at least 1.5 seconds following the         occurrence of (T₁); the computer determines a theoretical end of         test (TEOT) based on the determination of the zero order kinetic         rate. The computer may be programmed to determine the zero order         rate, which is expressed as a Line (L) in FIG. 6. The TEOT may         be determined by the corresponding time value (TEOT) along the         line L which corresponds with the quantity CEOT (i.e., that         corresponds with the value for T3);     -   (e) The computer 30 is programmed to ascertain the value for the         time to start (T₂S) which corresponds with the time at which the         simulated zero order kinetic rate begins.     -   (f) Following the detection of the acceleration of fibrinogen         conversion to detect the start time T₂S, the computer 30 is         programmed to detect for a deceleration of the fibrinogen         conversion, wherein the fibrinogen concentration decreases from         a predetermined quantity c_(MAP) to a predetermined quantity         c_(EOT) having a value which is about equal but less than the         first quantity c₁. The computer is programmed to ascertain a         first delta (IUTz), by determining the difference between the         quantity c_(T2S) and the quantity c_(EOT); and a second delta         (IUXz) by determining the difference between the quantity         c_(T2S) and the quantity c₂ (or c_(MAP).); the computer also         determines the value ZTM by determining the difference between         the time T₂ (which is Tmap) and the time T₂S;     -   (g) the computer 30 manipulates the collected data of (a); (b);         (c); (d), (e) and (f) above, to determine the new fibrinogen         transfer rate (nFTR). The nFTR may be arrived at based on the         principle that if a required amount (e.g., 0.05 g/l) of         fibrinogen concentration c₁ is first necessary to detect a clot         point (t₁); then when the fibrinogen concentration (c_(EOT))         becomes less than the required amount c₁, which occurs at time         (t_(EOT)), the fibrinogen end point has been reached. More         particularly, the required fibrinogen concentration c₁ is the         starting point of fibrinogen conversion of the clotting process         and the less than required fibrinogen concentration c_(EOT) is         the end point of the fibrinogen conversion of the clotting         process.     -   (h) the duration of the fibrinogen conversion of the clotting         process of the present invention is defined by the zero order         time period between TEOT and T₂S and is generally indicated in         FIG. 6 as IUTz. The difference between the corresponding         concentrations c_(T2S) and cT2 is used to define a delta IUXz.

The computer now has the information needed to determine the TEOT, which is expressed by the following formula:

TEOT=T2S+(ZTM/IUX*IUT)  (12)

-   -   The TEOT is determined and the data collected is manipulated by         the computer 30 to determine a new INR, referred to as INRn:

INRn=((T ₁+TEot)/2)*0.00535*T ₂ S  (11)

-   -   Using the multiplier MUL (which in this example, as discussed         herein and according to expression 10 above, preferably is         0.00535).

The computer 30 may be used to manipulate and derive the quantities of expression (11) to determine a new INR (INRn) utilizing known programming routines and techniques. The data collected by a computer 30 may be used to manipulate and derive INRn of expression (11). Similarly, one skilled in the art, using known mathematical techniques may derive the theoretical end of test TEOT of expression (5), and using the TEOT value in expression (11), in turn, may determine the new INR, INRn of expression (12). In the INRn determination, the determination is based on the patient's own sample, and does not rely on the determination of normal prothrombin times for the reagent used (e.g., thromboplastin, innovin or the like). With the INRn determination method, no longer does the accuracy of the quantities determined depend, in whole or part, on the number of specimens used, that is, the number of stable (or presumed stable) patients.

The new anticoagulation therapy value (INRn) does not require an ISI value, as was previously used to determine anticoagulation therapy factors. The new anticoagulation therapy value INRn uses for its ascertainment the values extracted from the clotting curve (see FIG. 6), in particular T₂S, Tmap, TEOT, c1, c_(T2S), ct2 and ceot. In determining the new INRn, the ISI is not required, nor is the MNPT, or the need to obtain and calculate the prothrombin times (PT's) for 20 presumed normal patients. In carrying out coagulation studies, the new anticoagulant therapy factor INRn may replace the INR traditionally used in anticoagulant therapy management (such as INR WHO and INRm). In addition, using the sample from the patient, the computer 30 has knowledge of the values obtained for the fibrinogen reaction, to ascertain the INRn.

It should now be appreciated that the present invention provides an apparatus and method for obtaining an new anticoagulant therapy value INRn without encountering the complications involved with obtaining the prior art quantities International Normalized Ratio (INR) and International Sensitivity Index (ISI).

The new International Normalized Ratio (INRn) preferably is a replacement for the International Normalized Ratio (INR) such as that of the WHO or the manufacturers of the clotting reagent that may provide an ISI for use with their particular clotting reagent. Existing medical literature, instrumentation, and methodologies are closely linked to the International Normalized Ratio (INR). The new INRn was compared for correlation with the INR by comparative testing, to INR quantities of INRw and INRm, even with the understanding that the INR determination may have an error of about +/−15%, at a 95% confidence interval, which needs to be taken into account to explain certain inconsistencies. The hereinbefore description of the new INRn does correlate at least as well as, and preferably better than, studies carried out using the traditional methods and determinations involving International Normalized Ratio (INR). For some comparisons, see the table above, and, in particular, Tables 11, 12 and 13.

While the invention has been described with reference to specific embodiments, the description is illustrative and is not to be construed as limiting the scope of the invention. The sample container used to contain the sample may comprise a vial, or cuvette, including, for example, the sample container disclosed in our U.S. Pat. No. 6,706,536. For example, although described in connection with body fluids of a human, the present invention has applicability to veterinary procedures, as well, where fluids are to be measured or analyzed. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention described herein and as defined by the appended claims. 

1. A method of determining a new anticoagulant therapy factor (nATF) comprising the steps of: a. determining for a sample of a bodily fluid the start (T₂S) of a zero order kinetic rate of conversion of fibrinogen to fibrin for a reaction of a reagent which reacts with fibrinogen present in the body fluid sample to convert the fibrinogen to fibrin, and a unit value corresponding to the start time (T₂S); b. determining the time to maximum acceleration (T map) for the rate of conversion of fibrinogen to fibrin for the body fluid sample; c. determining a first differential (IUX) based on the unit values obtained between the start (T₂S) of the zero order kinetic rate and the time to maximum acceleration (Tmap); d. determining a second differential (IUT) based on the unit values obtained between the theoretical end of test (TEOT) for the zero order kinetic rate, and the start (T₂S); e. determining a time differential ZTM based on the difference between T2S and T2; f. determining a theoretical end of test value (TEOT) by adding T2S to the value (ZTM/IUX*IUT); g. determining an anticoagulant therapy factor value (INRn) by taking the average of T1 and TEOT, multiplying the average by T2 and a multiplier MUL.
 2. The method of claim 1, wherein the multiplier MUL is based on a component relating to the sampling rate.
 3. The method of claim 1, wherein the multiplier MUL is based on a component relating to the pixel parity.
 4. The method of claim 2, wherein the multiplier MUL is further based on a component relating to the pixel parity.
 5. The method of claim 2, wherein said multiplier component is the fraction of the number of samples per time interval taken per unit of time.
 6. The method of claim 3, wherein said multiplier component is the pixel parity of the values of time and absorbance values, respectively of the x and y axes.
 7. The method of claim 6, wherein said multiplier component is further based on the fraction of the number of samples per time interval taken per unit of time.
 8. The method of claim 1, wherein said multiplier MUL is 0.00535.
 9. An apparatus for determining an anticoagulant therapy factor, said apparatus having a processor, and a computer chip preprogrammed with a set of instructions for cooperating with the output of a photodetection device which provides electrical data to said processor as a function of the optical density for a sample being analyzed, said apparatus having input means and storage means for storing data, said set of instructions including instructions for determining one or more anticoagulant therapy factors, including an international normalized ratio, INRn, through the transformation of time and absorbance values derived by reacting a sample of blood or blood component with a clotting reagent, recording time and absorbance values for at least (i) a time (T0) at which the sample and reagent are combined, (ii) a time (T1) corresponding with the beginning of the transformation of fibrinogen to fibrin from a reaction between the combined sample and reagent (T1), (iii) a time corresponding with the beginning of the maximum conversion rate of fibrinogen, (iv) a time corresponding with the ending of the maximum conversion rate of fibrinogen.
 10. The apparatus of claim 9, further comprising an article for deriving a value (INRn) useful for administration of treatment for a blood condition, the article including storage media with stored instructions which can be read and processed with a processor to determine an INRn value for a sample.
 11. An apparatus for determining an anticoagulant therapy factor, said apparatus having a processor, and a computer chip preprogrammed with a set of instructions for cooperating with the output of a photodetection device which provides electrical data to said processor as a function of the optical density for a sample being analyzed, said apparatus having input means and storage-means for storing data, said set of instructions including instructions for determining one or more anticoagulant therapy factors based on the steps set forth in claim
 1. 12. An apparatus for determining a new anticoagulant therapy factor (INRn) comprising: a. means including a light source, a test tube, a photocell, a battery, and a variable resistor all for developing an analog electric voltage signal having an amplitude proportional to an optical density of a liquid sample containing fibrinogen; b. means including an A/D converter and a computer both cooperating for converting and recording the developed analog signal into a series of digital voltage signal values; c. means for injecting a coagulant into a liquid sample, thereby producing an abrupt change in the optical density of the liquid sample, said abrupt change producing a change in the amplitude of the electrical analog signals, which, in turn, produces an abrupt change in the value of said digital voltage signals, the value of said digital voltage signals being directly indicative of fibrinogen concentration in the liquid sample; d. means, including a computer, for monitoring said voltage digital signal values for coagulant activity; e. means for recording an instant time (T₂S) the start of a zero order kinetic rate of conversion of fibrinogen to fibrin for a reaction of a reagent which reacts with fibrinogen present in the body fluid sample to convert the fibrinogen to fibrin, and a unit value corresponding to the start time (T₂S); f. means for recording a time to maximum acceleration (T map) for the rate of conversion of fibrinogen to fibrin for the body fluid sample; g. means, including said computer, for monitoring voltage digital signal values at times T₂S and the time to maximum acceleration (T map) for respective predetermined fibrinogen concentration quantities c_(T2S) and c_(Tmap), and for calculating the difference between quantities c_(T2S) and c_(T2) to provide a first differential (IUX_(t)); h. means, including said computer, for monitoring voltage digital signal values at times T₂S and the time to maximum acceleration (Tmap) for respective predetermined fibrinogen concentration quantities c_(T2S) and c_(Tmap), and for calculating the difference between quantities c_(T2S) and c_(T2) to provide a first differential (IUX_(t)); i. means, including said computer, for determining a time differential ZTM based on the difference between T2S and T2; j. means, including said computer, for determining a theoretical end of test value (TEOT) by adding T2S to the value (ZTM/IUX*IUT); k. means, including said computer, for determining an anticoagulant therapy factor value (INRn) by taking the average of T1 and TEOT, and multiplying the average by T2 and a multiplier MUL.
 13. An article for deriving an anticoagulant therapy factor (INRn), the article including storage media configured with stored instructions which can be read and processed with a processor to determine an INRn value for a sample of blood or a blood component based on determining absorbance values of the sample and reagent combined therewith that correspond with a clotting component of a coagulation reaction involving said reagent and said sample, for times (i) when the reagent and sample are combined, (ii) when the reaction between the reagent and the sample begins to form a change in absorbance values as a result of a clot formation, (iii) the beginning of the time at which the maximum rate of conversion of a clotting component of the sample occurs, (iv) the end of the time at which the maximum rate of conversion of a clotting component of the sample occurs, and (v) the time at which the absorbance values for the rate of conversion for the clotting component approaches zero.
 14. A method for determining a coagulation parameter for a blood or blood component of a living being, comprising: reacting a sample of blood or a blood component containing fibrinogen with a clotting agent by combining said blood sample with said clotting agent; recording, with recording means for making optical measurements, time and absorbance values for the sample during the reaction with the clotting agent; determining a slope corresponding with the maximum acceleration rate of transformation of fibrinogen to fibrin; determining an end of test time (TEOT) corresponding with an absorbance value (cEOT) that is indicative of a substantial completion of the reaction of the sample and clotting agent, wherein said time (TEOT) corresponds with the time at which a line of said slope intersects said absorbance value (cEOT); determining the absorbance value (c1) at the time the sample and reagent are begin to form a change in clotting activity (T1); determining a time to maximum acceleration for the transformation from fibrinogen to fibrin; determining an INR value, INRn, for the sample.
 15. The method of claim 14, wherein obtaining an INRn value includes determining an area of a trapezoid formed by a clotting curve, wherein at least one point of said trapezoid comprises the time value TEOT.
 16. The method of claim 15, wherein said TEOT value is one base of said trapezoid, and wherein said difference in value between (cEOT) and value c1, comprises the altitude of said trapezoid.
 17. The method of claim 16, wherein said second base of said trapezoid is the value T1.
 18. The method of claim 14, wherein recording, with recording means for making optical measurements, time and absorbance values for the sample during the reaction with the clotting agent includes developing a series of analog electrical voltage signals having voltage amplitudes proportional to an optical density of a clotting component of said sample.
 19. The method of claim 18, wherein the clotting component comprises fibrinogen.
 20. The method of claim 18, wherein said determination of an INRn value is expressed by the following relationship: INRn=((T₁+TEot)/2)*0.00535* T₂S 